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To enable debugging of the Ethernet management port, use the debug fastethernet command in EXEC mode. To disable debugging, use the no form of this command.
debug fastethernet { af | events | packets }
no debug fastethernet { af | events | packets }
af |
Displays Ethernet management port software-address-filter debug messages. |
events |
Displays Ethernet management port event debug messages. |
packets |
Displays Ethernet management port packet debug messages. |
Debugging is disabled.
User EXEC
Privileged EXEC
This command was introduced. |
The undebug fastethernet { af | events | packets} command is the same as the no debug fastethernet{af| events | packets} command.
When you enable debugging on a switch stack, it is enabled only on the stack master. To enable debugging on a stack member, you can start a session from the stack master by using the session switch-number EXEC command. Then enter the debug command at the command-line prompt of the stack member. You also can use the remote command stack-member-number LINE EXEC command on the stack master switch to enable debugging on a member switch without first starting a session.
Command |
Description |
---|---|
show debugging |
Displays information about the types of debugging that are enabled. |
To enable debugging of the power controller and Power over Ethernet (PoE) system, use the debug ilpower command in privileged EXEC mode. To disable debugging, use the no form of this command.
debug ilpower { cdp | controller | event | ha | police | port | powerman | registries | scp | sense }
no debug ilpower { cdp | controller | event | ha | police | port | powerman | registries | scp | sense }
cdp |
Displays PoE Cisco Discovery Protocol (CDP) debug messages. |
controller |
Displays PoE controller debug messages. |
event |
Displays PoE event debug messages. |
ha |
Displays PoE high-availability messages. |
police |
Displays PoE police debug messages. |
port |
Displays PoE port manager debug messages. |
powerman |
Displays PoE power management debug messages. |
registries |
Displays PoE registries debug messages. |
scp |
Displays PoE SCP debug messages. |
sense |
Displays PoE sense debug messages. |
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This command is supported only on PoE-capable switches.
When you enable debugging on a switch stack, it is enabled only on the stack master. To enable debugging on a stack member, you can start a session from the stack master by using the session switch-number EXEC command. Then enter the debug command at the command-line prompt of the stack member. You also can use the remote command stack-member-number LINE EXEC command on the stack master switch to enable debugging on a member switch without first starting a session.
To enable debugging of interface-related activities, use the debug interface command in privileged EXEC mode. To disable debugging, use the no form of this command.
debug interface { interface-id | counters { exceptions | protocol memory } | null interface-number | port-channel port-channel-number | states| vlan vlan-id }
no debug interface { interface-id | counters { exceptions | protocol memory } | null interface-number | port-channel port-channel-number | states| vlan vlan-id }
interface-id |
ID of the physical interface. Displays debug messages for the specified physical port, identified by type switch number/module number/port, for example, gigabitethernet 1/0/2. |
null interface-number |
Displays debug messages for null interfaces. The interface number is always 0. |
port-channel port-channel-number |
Displays debug messages for the specified EtherChannel port-channel interface. The port-channel-number range is 1 to 48. |
vlan vlan-id |
Displays debug messages for the specified VLAN. The vlan range is 1 to 4094. |
counters |
Displays counters debugging information. |
exceptions |
Displays debug messages when a recoverable exceptional condition occurs during the computation of the interface packet and data rate statistics. |
protocol memory |
Displays debug messages for memory operations of protocol counters. |
states |
Displays intermediary debug messages when an interface's state transitions. |
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
If you do not specify a keyword, all debug messages appear.
The undebug interface command is the same as the no debug interface command.
When you enable debugging on a switch stack, it is enabled only on the stack master. To enable debugging on a stack member, you can start a session from the stack master by using the session switch-number EXEC command. Then enter the debug command at the command-line prompt of the stack member. You also can use the remote command stack-member-number LINE EXEC command on the stack master switch to enable debugging on a member switch without first starting a session.
To enable debugging of Link Layer Discovery Protocol (LLDP) packets, use the debug lldp packets command in privileged EXEC mode. To disable debugging, use the no form of this command.
debug lldp packets
no debug lldp packets
This command has no arguments or keywords.
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
The undebug lldp packets command is the same as the no debug lldp packets command.
When you enable debugging on a switch stack, it is enabled only on the stack master. To enable debugging on a stack member, you can start a session from the stack master by using the session switch-number EXEC command.
To enable debugging of the Network Mobility Services Protocol (NMSP) on the switch, use the debug nmsp command in privileged EXEC mode. To disable debugging, use the no form of this command.
debug nmsp { all | connection | error | event | message | packet | rx | tx }
no debug nmsp { all | connection | error | event | message | packet | rx | tx }
all |
Displays all NMSP debug messages. |
connection |
Displays debug messages for NMSP connection events. |
error |
Displays debugging information for NMSP error messages. |
event |
Displays debug messages for NMSP events. |
message |
Displays debugging information for NMSP messages. |
rx |
Displays debugging information for NMSP receive messages. |
tx |
Displays debugging information for NMSP transmit messages. |
packet |
Displays debug messages for NMSP packet events. |
Debugging is disabled.
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
The undebug nmsp command is the same as the no debug nmsp command.
When you enable debugging on a switch stack, it is enabled only on the stack master. To enable debugging on a stack member, you can start a session from the stack master by using the session switch-number EXEC command. Then enter the debug command at the command-line prompt of the stack member. You also can use the remote command stack-member-number LINE EXEC command on the stack master switch to enable debugging on a member switch without first starting a session.
To specify the duplex mode of operation for a port, use the duplex command in interface configuration mode. To return to the default value, use the no form of this command.
duplex { auto | full | half }
no duplex { auto | full | half }
auto |
Enables automatic duplex configuration. The port automatically detects whether it should run in full- or half-duplex mode, depending on the attached device mode. |
full |
Enables full-duplex mode. |
half |
Enables half-duplex mode (only for interfaces operating at 10 or 100 Mb/s). You cannot configure half-duplex mode for interfaces operating at 1000 or 10,000 Mb/s. |
The default is auto for Fast Ethernet and Gigabit Ethernet ports.
The default is half for 100BASE-x (where -x is -BX, -FX, -FX-FE, or -LX) SFP modules.
Duplex options are not supported on the 1000BASE-x or 10GBASE-x (where -x is -BX, -CWDM, -LX, -SX, or -ZX) small form-factor pluggable (SFP) modules.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
For Fast Ethernet ports, setting the port to auto has the same effect as specifying half if the attached device does not autonegotiate the duplex parameter.
For Gigabit Ethernet ports, setting the port to auto has the same effect as specifying full if the attached device does not autonegotiate the duplex parameter.
![]() Note | Half-duplex mode is supported on Gigabit Ethernet interfaces if the duplex mode is auto and the connected device is operating at half duplex. However, you cannot configure these interfaces to operate in half-duplex mode. |
Certain ports can be configured to be either full duplex or half duplex. How this command is applied depends on the device to which the switch is attached.
If both ends of the line support autonegotiation, we highly recommend using the default autonegotiation settings. If one interface supports autonegotiation and the other end does not, configure duplex and speed on both interfaces, and use the auto setting on the supported side.
If the speed is set to auto, the switch negotiates with the device at the other end of the link for the speed setting and then forces the speed setting to the negotiated value. The duplex setting remains as configured on each end of the link, which could result in a duplex setting mismatch.
You can configure the duplex setting when the speed is set to auto.
![]() Caution | Changing the interface speed and duplex mode configuration might shut down and reenable the interface during the reconfiguration. |
You can verify your setting by entering the show interfaces privileged EXEC command.
This example shows how to configure an interface for full-duplex operation:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# duplex full
To enable error-disable detection for a specific cause or for all causes, use the errdisable detect cause command in global configuration mode. To disable the error-disable detection feature, use the no form of this command.
errdisable detect cause { all | arp-inspection | bpduguard shutdown vlan | dhcp-rate-limit | dtp-flap | gbic-invalid | inline-power | l2ptguard | link-flap | loopback | pagp-flap | pppoe-ia-rate-limit | psp shutdown vlan | security-violation shutdown vlan | sfp-config-mismatch }
no errdisable detect cause { all | arp-inspection | bpduguard shutdown vlan | dhcp-rate-limit | dtp-flap | gbic-invalid | inline-power | l2ptguard | link-flap | loopback | pagp-flap | pppoe-ia-rate-limit | psp shutdown vlan | security-violation shutdown vlan | sfp-config-mismatch }
all |
Enables error detection for all error-disabled causes. |
||
arp-inspection |
Enables error detection for dynamic Address Resolution Protocol (ARP) inspection. |
||
bpduguard shutdown vlan |
Enables per-VLAN error-disable for BPDU guard. |
||
dhcp-rate-limit |
Enables error detection for DHCP snooping. |
||
dtp-flap |
Enables error detection for the Dynamic Trunking Protocol (DTP) flapping. |
||
gbic-invalid |
Enables error detection for an invalid Gigabit Interface Converter (GBIC) module.
|
||
inline-power |
Enables error detection for the Power over Ethernet (PoE) error-disabled cause.
|
||
l2ptguard |
Enables error detection for a Layer 2 protocol-tunnel error-disabled cause. |
||
link-flap |
Enables error detection for link-state flapping. |
||
loopback |
Enables error detection for detected loopbacks. |
||
pagp-flap |
Enables error detection for the Port Aggregation Protocol (PAgP) flap error-disabled cause. |
||
pppoe-ia-rate-limit |
Enables error detection for the PPPoE Intermediate Agent rate-limit error-disabled cause. |
||
psp shutdown vlan |
Enables error detection for protocol storm protection (PSP). |
||
security-violation shutdown vlan |
Enables voice aware 802.1x security. |
||
sfp-config-mismatch |
Enables error detection on an SFP configuration mismatch. |
Detection is enabled for all causes. All causes, except per-VLAN error disabling, are configured to shut down the entire port.
Global configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
A cause (such as a link-flap or dhcp-rate-limit) is the reason for the error-disabled state. When a cause is detected on an interface, the interface is placed in an error-disabled state, an operational state that is similar to a link-down state.
When a port is error-disabled, it is effectively shut down, and no traffic is sent or received on the port. For the bridge protocol data unit (BPDU) guard, voice-aware 802.1x security, and port-security features, you can configure the switch to shut down only the offending VLAN on the port when a violation occurs, instead of shutting down the entire port.
If you set a recovery mechanism for the cause by entering the errdisable recovery global configuration command, the interface is brought out of the error-disabled state and allowed to retry the operation when all causes have timed out. If you do not set a recovery mechanism, you must enter the shutdown and then the no shutdown commands to manually recover an interface from the error-disabled state.
For protocol storm protection, excess packets are dropped for a maximum of two virtual ports. Virtual port error disabling using the psp keyword is not supported for EtherChannel and Flexlink interfaces.
To verify your settings, enter the show errdisable detect privileged EXEC command.
This example shows how to enable error-disabled detection for the link-flap error-disabled cause:
Switch(config)# errdisable detect cause link-flap
This command shows how to globally configure BPDU guard for a per-VLAN error-disabled state:
Switch(config)# errdisable detect cause bpduguard shutdown vlan
This command shows how to globally configure voice-aware 802.1x security for a per-VLAN error-disabled state:
Switch(config)# errdisable detect cause security-violation shutdown vlan
You can verify your setting by entering the
show
errdisable
detect privileged EXEC command.
To allow any switch port to be error disabled if incoming VLAN-tagged packets are small frames (67 bytes or less) and arrive at the minimum configured rate (the threshold), use the errdisable detect cause small-frame global configuration command on the switch stack or on a standalone switch. Use the no form of this command to return to the default setting.
errdisable detect cause small-frame
no errdisable detect cause small-frame
This command has no arguments or keywords.
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This command globally enables the small-frame arrival feature. Use the small violation-rate interface configuration command to set the threshold for each port.
You can configure the port to be automatically re-enabled by using the errdisable recovery cause small-frame global configuration command. You configure the recovery time by using the errdisable recovery interval interval global configuration command.
This example shows how to enable the switch ports to be put into the error-disabled mode if incoming small frames arrive at the configured threshold:
Switch(config)# errdisable detect cause small-frame
You can verify your setting by entering the show interfaces privileged EXEC command.
To enable the error-disabled mechanism to recover from a specific cause, use the errdisable recovery cause command in global configuration mode. To return to the default setting, use the no form of this command.
errdisable recovery cause { all | arp-inspection | bpduguard | channel-misconfig | dhcp-rate-limit | dtp-flap | gbic-invalid | inline-power | l2ptguard | link-flap | loopback | mac-limit | pagp-flap | port-mode-failure | pppoe-ia-rate-limit | psecure-violation | psp | security-violation | sfp-config-mismatch | storm-control | udld | vmps }
no errdisable recovery cause { all | arp-inspection | bpduguard | channel-misconfig | dhcp-rate-limit | dtp-flap | gbic-invalid | inline-power | l2ptguard | link-flap | loopback | mac-limit | pagp-flap | port-mode-failure | pppoe-ia-rate-limit | psecure-violation | psp | security-violation | sfp-config-mismatch | storm-control | udld | vmps }
all |
Enables the timer to recover from all error-disabled causes. |
||
arp-inspection |
Enables the timer to recover from the Address Resolution Protocol (ARP) inspection error-disabled state. |
||
bpduguard |
Enables the timer to recover from the bridge protocol data unit (BPDU) guard error-disabled state. |
||
channel-misconfig |
Enables the timer to recover from the EtherChannel misconfiguration error-disabled state. |
||
dhcp-rate-limit |
Enables the timer to recover from the DHCP snooping error-disabled state. |
||
dtp-flap |
Enables the timer to recover from the Dynamic Trunking Protocol (DTP) flap error-disabled state. |
||
gbic-invalid |
Enables the timer to recover from an invalid Gigabit Interface Converter (GBIC) module error-disabled state.
|
||
inline-power |
Enables the timer to recover from the Power over Ethernet (PoE) error-disabled state. This keyword is supported only on switches with PoE ports. |
||
l2ptguard |
Enables the timer to recover from a Layer 2 protocol tunnel error-disabled state. |
||
link-flap |
Enables the timer to recover from the link-flap error-disabled state. |
||
loopback |
Enables the timer to recover from a loopback error-disabled state. |
||
mac-limit |
Enables the timer to recover from the mac limit error-disabled state. |
||
pagp-flap |
Enables the timer to recover from the Port Aggregation Protocol (PAgP)-flap error-disabled state. |
||
port-mode-failure |
Enables the timer to recover from the port mode change failure error-disabled state. |
||
pppoe-ia-rate-limit |
Enables the timer to recover from the PPPoE IA rate limit error-disabled state. |
||
psecure-violation |
Enables the timer to recover from a port security violation disable state. |
||
psp |
Enables the timer to recover from the protocol storm protection (PSP) error-disabled state. |
||
security-violation |
Enables the timer to recover from an IEEE 802.1x-violation disabled state. |
||
sfp-config-mismatch |
Enables error detection on an SFP configuration mismatch. |
||
storm-control |
Enables the timer to recover from a storm control error. |
||
udld |
Enables the timer to recover from the UniDirectional Link Detection (UDLD) error-disabled state. |
||
vmps |
Enables the timer to recover from the VLAN Membership Policy Server (VMPS) error-disabled state. |
Recovery is disabled for all causes.
Global configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
A cause (such as all or BDPU guard) is defined as the reason that the error-disabled state occurred. When a cause is detected on an interface, the interface is placed in the error-disabled state, an operational state similar to link-down state.
When a port is error-disabled, it is effectively shut down, and no traffic is sent or received on the port. For the BPDU guard and port-security features, you can configure the switch to shut down only the offending VLAN on the port when a violation occurs, instead of shutting down the entire port.
If you do not enable the recovery for the cause, the interface stays in the error-disabled state until you enter the shutdown and the no shutdown interface configuration commands. If you enable the recovery for a cause, the interface is brought out of the error-disabled state and allowed to retry the operation again when all the causes have timed out.
Otherwise, you must enter the shutdown and then the no shutdown commands to manually recover an interface from the error-disabled state.
You can verify your settings by entering the show errdisable recovery privileged EXEC command.
This example shows how to enable the recovery timer for the BPDU guard error-disabled cause:
Switch(config)# errdisable recovery cause bpduguard
Use the errdisable recovery cause small-frame global configuration command on the switch to enable the recovery timer for ports to be automatically re-enabled after they are error disabled by the arrival of small frames. Use the no form of this command to return to the default setting.
errdisable recovery cause small-frame
no errdisable recovery cause small-frame
This command has no arguments or keywords.
This feature is disabled.
Global configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This command enables the recovery timer for error-disabled ports. You configure the recovery time by using the errdisable recovery interval interface configuration command.
This example shows how to set the recovery timer:
Switch(config)# errdisable recovery cause small-frame
To specify the time to recover from an error-disabled state, use the errdisable recovery interval command in global configuration mode. To return to the default setting, use the no form of this command.
errdisable recovery interval timer-interval
no errdisable recovery interval timer-interval
timer-interval |
Time to recover from the error-disabled state. The range is 30 to 86400 seconds. The same interval is applied to all causes. The default interval is 300 seconds. |
The default recovery interval is 300 seconds.
Global configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
The error-disabled recovery timer is initialized at a random differential from the configured interval value. The difference between the actual timeout value and the configured value can be up to 15 percent of the configured interval.
You can verify your settings by entering the show errdisable recovery privileged EXEC command.
This example shows how to set the timer to 500 seconds:
Switch(config)# errdisable recovery interval 500
To enable Link Layer Discovery Protocol (LLDP) on an interface, use the lldp command in interface configuration mode. To disable LLDP on an interface, use the no form of this command.
lldp { med-tlv-select tlv | receive | tlv-select { 4-wire-power-management | power-management} | transmit }
no lldp { med-tlv-select tlv | receive | tlv-select { 4-wire-power-management | power-management} | transmit }
med-tlv-select |
Selects an LLDP Media Endpoint Discovery (MED) time-length-value (TLV) element to send. |
tlv |
String that identifies the TLV element. Valid values are the following: |
receive |
Enables the interface to receive LLDP transmissions. |
tlv-select |
Selects the LLDP TLVs to send. |
4-wire-power-management |
Sends the Cisco 4-wire Power Management TLV. |
power-management |
Sends the LLDP Power Management TLV. |
transmit |
Enables LLDP transmission on the interface. |
LLDP is enabled on supported interfaces.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This command is supported on 802.1 media types.
If the interface is configured as a tunnel port, LLDP is automatically disabled.
The following example shows how to disable LLDP transmission on an interface:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# no lldp transmit
The following example shows how to enable LLDP transmission on an interface:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# lldp transmit
To enable the automatic medium-dependent interface crossover (auto-MDIX) feature on the interface, use the mdix auto command in interface configuration mode. To disable auto-MDIX, use the no form of this command.
mdix auto
no mdix auto
This command has no arguments or keywords.
Auto-MDIX is enabled.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
When auto-MDIX is enabled, the interface automatically detects the required cable connection type (straight-through or crossover) and configures the connection appropriately.
When you enable auto-MDIX on an interface, you must also set the interface speed and duplex to auto so that the feature operates correctly.
When auto-MDIX (and autonegotiation of speed and duplex) is enabled on one or both of the connected interfaces, link up occurs, even if the cable type (straight-through or crossover) is incorrect.
Auto-MDIX is supported on all 10/100 and 10/100/1000 Mb/s interfaces and on 10/100/1000BASE-TX small form-factor pluggable (SFP) module interfaces. It is not supported on 1000BASE-SX or -LX SFP module interfaces.
You can verify the operational state of auto-MDIX on the interface by entering the show controllers ethernet-controller interface-id phy privileged EXEC command.
This example shows how to enable auto-MDIX on a port:
Switch# configure terminal Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# speed auto Switch(config-if)# duplex auto Switch(config-if)# mdix auto Switch(config-if)# end
To apply a network-policy profile to an interface, use the network-policy command in interface configuration mode. To remove the policy, use the no form of this command.
network-policy profile-number
no network-policy
profile-number |
The network-policy profile number to apply to the interface. |
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Use the network-policy profile number interface configuration command to apply a profile to an interface.
You cannot apply the switchport voice vlan command on an interface if you first configure a network-policy profile on it. However, if switchport voice vlan vlan-id is already configured on the interface, you can apply a network-policy profile on the interface. The interface then has the voice or voice-signaling VLAN network-policy profile applied.
This example shows how to apply network-policy profile 60 to an interface:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# network-policy 60
To create a network-policy profile and to enter network-policy configuration mode, use the network-policy profile command in global configuration mode. To delete the policy and to return to global configuration mode, use the no form of this command.
network-policy profile profile-number
no network-policy profile profile-number
profile-number |
Network-policy profile number. The range is 1 to 4294967295. |
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Use the network-policy profile global configuration command to create a profile and to enter network-policy profile configuration mode.
To return to privileged EXEC mode from the network-policy profile configuration mode, enter the exit command.
When you are in network-policy profile configuration mode, you can create the profile for voice and voice signaling by specifying the values for VLAN, class of service (CoS), differentiated services code point (DSCP), and tagging mode.
These profile attributes are contained in the Link Layer Discovery Protocol for Media Endpoint Devices (LLDP-MED) network-policy time-length-value (TLV).
This example shows how to create network-policy profile 60:
Switch(config)# network-policy profile 60 Switch(config-network-policy)#
To suppress the reporting of attachment information from a specified interface, use the nmsp attachment suppress command in interface configuration mode. To return to the default setting, use the no form of this command.
nmsp attachment suppress
no nmsp attachment suppress
This command has no arguments or keywords.
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Use the nmsp attachment suppress interface configuration command to configure an interface to not send location and attachment notifications to a Cisco Mobility Services Engine (MSE).
This example shows how to configure an interface to not send attachment information to the MSE:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# nmsp attachment suppress
To enable Energy Efficient Ethernet (EEE) for an interface, use the power efficient-ethernet auto command in interface configuration mode. To disable EEE on an interface, use the no form of this command.
power efficient-ethernet auto
no power efficient-ethernet auto
This command has no arguments or keywords.
EEE is disabled.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
You can enable EEE on devices that support low power idle (LPI) mode. Such devices can save power by entering LPI mode during periods of low utilization. In LPI mode, systems on both ends of the link can save power by shutting down certain services. EEE provides the protocol needed to transition into and out of LPI mode in a way that is transparent to upper layer protocols and applications.
The power efficient-ethernet auto command is available only if the interface is EEE capable. To check if an interface is EEE capable, use the show eee capabilities EXEC command.
When EEE is enabled, the switch advertises and autonegotiates EEE to its link partner. To view the current EEE status for an interface, use the show eee status EXEC command.
This command does not require a license.
This example shows how to enable EEE for an interface:
Switch(config-if)# power efficient-ethernet auto Switch(config-if)#
This example shows how to disable EEE for an interface:
Switch(config-if)# no power efficient-ethernet auto Switch(config-if)#
To configure the power management mode on Power over Ethernet (PoE) ports, use the power inline command in interface configuration mode. To return to the default settings, use the no form of this command.
power inline { auto [ max max-wattage ] | never | port priority { high | low } | static [ max max-wattage ] }
no power inline { auto | never | port priority { high | low } | static [ max max-wattage ] }
auto |
Enables powered-device detection. If enough power is available, automatically allocates power to the PoE port after device detection. Allocation is first-come, first-serve. |
max max-wattage |
(Optional) Limits the power allowed on the port. The range is 4000 to 30000 mW. If no value is specified, the maximum is allowed. |
never |
Disables device detection, and disables power to the port. |
port |
Configures the power priority of the port. The default priority is low. |
priority {high|low} |
Sets the power priority of the port. In case of a power supply failure, ports configured as low priority are turned off first and ports configured as high priority are turned off last. The default priority is low. |
static |
Enables powered-device detection. Pre-allocates (reserves) power for a port before the switch discovers the powered device. This action guarantees that the device connected to the interface receives enough power. |
The default is auto (enabled).
The maximum wattage is 30,000 mW.
The default port priority is low.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This command is supported only on PoE-capable ports. If you enter this command on a port that does not support PoE, this error message appears:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# power inline auto ^ % Invalid input detected at '^' marker.
In a switch stack, this command is supported on all ports in the stack that support PoE.
Use the max max-wattage option to disallow higher-power powered devices. With this configuration, when the powered device sends Cisco Discovery Protocol (CDP) messages requesting more power than the maximum wattage, the switch removes power from the port. If the powered-device IEEE class maximum is greater than the maximum wattage, the switch does not power the device. The power is reclaimed into the global power budget.
![]() Note | The switch never powers any class 0 or class 3 device if the power inline max max-wattage command is configured for less than 30 W. |
If the switch denies power to a powered device (the powered device requests more power through CDP messages or if the IEEE class maximum is greater than the maximum wattage), the PoE port is in a power-deny state. The switch generates a system message, and the Oper column in the show power inline privileged EXEC command output shows power-deny.
Use the power inline static max max-wattage command to give a port high priority. The switch allocates PoE to a port configured in static mode before allocating power to a port configured in auto mode. The switch reserves power for the static port when it is configured rather than upon device discovery. The switch reserves the power on a static port even when there is no connected device and whether or not the port is in a shutdown or in a no shutdown state. The switch allocates the configured maximum wattage to the port, and the amount is never adjusted through the IEEE class or by CDP messages from the powered device. Because power is pre-allocated, any powered device that uses less than or equal to the maximum wattage is guaranteed power when it is connected to a static port. However, if the powered device IEEE class is greater than the maximum wattage, the switch does not supply power to it. If the switch learns through CDP messages that the powered device needs more than the maximum wattage, the powered device is shut down.
If the switch cannot pre-allocate power when a port is in static mode (for example, because the entire power budget is already allocated to other auto or static ports), this message appears: Command rejected: power inline static: pwr not available. The port configuration remains unchanged.
When you configure a port by using the power inline auto or the power inline static interface configuration command, the port autonegotiates by using the configured speed and duplex settings. This is necessary to determine the power requirements of the connected device (whether or not it is a powered device). After the power requirements have been determined, the switch hardcodes the interface by using the configured speed and duplex settings without resetting the interface.
When you configure a port by using the power inline never command, the port reverts to the configured speed and duplex settings.
If a port has a Cisco powered device connected to it, you should not use the power inline never command to configure the port. A false link-up can occur, placing the port in an error-disabled state.
Use the power inline port priority {high | low} command to configure the power priority of a PoE port. Powered devices connected to ports with low port priority are shut down first in case of a power shortage.
You can verify your settings by entering the show power inline EXEC command.
This example shows how to enable detection of a powered device and to automatically power a PoE port on a switch:
Switch(config)# interface gigabitethernet1/0/2 Switch(config-if)# power inline auto
This example shows how to configure a PoE port on a switch to allow a class 1 or a class 2 powered device:
Switch(config)# interface gigabitethernet1/0/2 Switch(config-if)# power inline auto max 7000
This example shows how to disable powered-device detection and to not power a PoE port on a switch:
Switch(config)# interface gigabitethernet1/0/2 Switch(config-if)# power inline never
This example shows how to set the priority of a port to high, so that it would be one of the last ports to be shut down in case of power supply failure:
Switch(config)# interface gigabitethernet1/0/2 Switch(config-if)# power inline port priority high
To override the amount of power specified by the IEEE classification for a powered device, use the power inline consumption command in global or interface configuration to specify the wattage used by each device. To return to the default power setting, use the no form of this command.
power inline consumption [default] wattage
no power inline consumption [default]
default |
The default keyword appears only in the global configuration. The command has the same effect with or without the keyword. |
wattage |
Specifies the power that the switch budgets for the port. The range is 4000 to 15400 mW. |
The default power on each Power over Ethernet (PoE) port is15400 mW.
Global configuration
Interface configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This command is supported only on the LAN Base image.
When Cisco powered devices are connected to PoE ports, the switch uses Cisco Discovery Protocol (CDP) to determine the CDP-specific power consumption of the devices, which is the amount of power to allocate based on the CDP messages. The switch adjusts the power budget accordingly. This does not apply to IEEE third-party powered devices. For these devices, when the switch grants a power request, the switch adjusts the power budget according to the powered-device IEEE classification. If the powered device is a class 0 (class status unknown) or a class 3, the switch budgets 15400 mW for the device, regardless of the CDP-specific amount of power needed.
If the powered device reports a higher class than its CDP-specific consumption or does not support power classification (defaults to class 0), the switch can power fewer devices because it uses the IEEE class information to track the global power budget.
With PoE+, powered devices use IEEE 802.3at and LLDP power with media dependent interface (MDI) type, length, and value descriptions (TLVs), Power-via-MDA TLVs, for negotiating power up to 30 W. Cisco pre-standard devices and Cisco IEEE powered devices can use CDP or the IEEE 802.3at power-via-MDI power negotiation mechanism to request power levels up to 30 W.
![]() Note | The initial allocation for Class 0, Class 3, and Class 4 powered devices is 15.4 W. When a device starts up and uses CDP or LLDP to send a request for more than 15.4 W, it can be allocated up to the maximum of 30 W. |
By using the power inline consumption wattage configuration command, you can override the default power requirement of the IEEE classification. The difference between what is mandated by the IEEE classification and what is actually needed by the device is reclaimed into the global power budget for use by additional devices. You can then extend the switch power budget and use it more effectively.
Before entering the power inline consumption wattage configuration command, we recommend that you enable policing of the real-time power consumption by using the power inline police [action log] interface configuration command.
![]() Caution | You should carefully plan your switch power budget and make certain not to oversubscribe the power supply. |
When you enter the power inline consumption default wattage or the no power inline consumption default global configuration command, or the power inline consumption wattage or the no power inline consumption interface configuration command, this caution message appears.
%CAUTION: Interface Gi1/0/1: Misconfiguring the 'power inline consumption/allocation' command may cause damage to the switch and void your warranty. Take precaution not to oversubscribe the power supply. It is recommended to enable power policing if the switch supports it. Refer to documentation.
![]() Note | When you manually configure the power budget, you must also consider the power loss over the cable between the switch and the powered device. |
For more information about the IEEE power classifications, see the “Configuring Interface Characteristics” chapter in the software configuration guide for this release.
This command is supported only on PoE-capable ports. If you enter this command on a switch or port that does not support PoE, an error message appears.
In a switch stack, this command is supported on all switches or ports in the stack that support PoE.
You can verify your settings by entering the show power inline consumption privileged EXEC command.
This example shows how to use the command in global configuration mode to configure the switch to budget 5000 mW to each PoE port:
Switch(config)# power inline consumption default 5000
%CAUTION: Interface Gi1/0/1: Misconfiguring the 'power inline consumption/allocation' command may cause damage to the switch and void your warranty. Take precaution not to oversubscribe the power supply.
It is recommended to enable power policing if the switch supports it.
Refer to documentation.
This example shows how to use the command in interface configuration mode to configure the switch to budget 12000 mW to the powered device connected to a specific PoE port:
Switch(config)# interface gigabitethernet1/0/2 Switch(config-if)# power inline consumption 12000 %CAUTION: Interface Gi1/0/2: Misconfiguring the 'power inline consumption/allocation' command may cause damage to the switch and void your warranty. Take precaution not to oversubscribe the power supply. It is recommended to enable power policing if the switch supports it. Refer to documentation.
To enable policing of real-time power consumption on a powered device, use the power inline police command in interface configuration mode. To disable this feature, use the no form of this command
power inline police [ action { errdisable | log } ]
no power inline police
action errdisable |
(Optional) Configures the switch to turn off power to the port if the real-time power consumption exceeds the maximum power allocation on the port. This is the default action. |
action log |
(Optional) Configures the switch to generate a syslog message while still providing power to a connected device if the real-time power consumption exceeds the maximum power allocation on the port. |
Policing of the real-time power consumption of the powered device is disabled.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This command is supported only on the LAN Base image.
This command is supported only on Power over Ethernet (PoE)-capable ports. If you enter this command on a switch or port that does not support PoE, an error message appears.
In a switch stack, this command is supported on all switches or ports in the stack that support PoE and real-time power-consumption monitoring.
When policing of the real-time power consumption is enabled, the switch takes action when a powered device consumes more power than the allocated maximum amount.
When PoE is enabled, the switch senses the real-time power consumption of the powered device. This feature is called power monitoring or power sensing. The switch also polices the power usage with the power policing feature.
When power policing is enabled, the switch uses one of the these values as the cutoff power on the PoE port in this order:
The switch automatically sets the power usage of the device by using CDP power negotiation or by the IEEE classification and LLPD power negotiation.
If you do not manually configure the cutoff-power value, the switch automatically determines it by using CDP power negotiation or the device IEEE classification and LLDP power negotiation. If CDP or LLDP are not enabled, the default value of 30 W is applied. However without CDP or LLDP, the switch does not allow devices to consume more than 15.4 W of power because values from 15400 to 30000 mW are only allocated based on CDP or LLDP requests. If a powered device consumes more than 15.4 W without CDP or LLDP negotiation, the device might be in violation of the maximum current Imax limitation and might experience an Icut fault for drawing more current than the maximum. The port remains in the fault state for a time before attempting to power on again. If the port continuously draws more than 15.4 W, the cycle repeats.
When a powered device connected to a PoE+ port restarts and sends a CDP or LLDP packet with a power TLV, the switch locks to the power-negotiation protocol of that first packet and does not respond to power requests from the other protocol. For example, if the switch is locked to CDP, it does not provide power to devices that send LLDP requests. If CDP is disabled after the switch has locked on it, the switch does not respond to LLDP power requests and can no longer power on any accessories. In this case, you should restart the powered device.
If power policing is enabled, the switch polices power usage by comparing the real-time power consumption to the maximum power allocated on the PoE port. If the device uses more than the maximum power allocation (or cutoff power) on the port, the switch either turns power off to the port, or the switch generates a syslog message and updates the LEDs (the port LEDs are blinking amber) while still providing power to the device.
To configure the switch to turn off power to the port and put the port in the error-disabled state, use the power inline police interface configuration command.
To configure the switch to generate a syslog message while still providing power to the device, use the power inline police action log command.
If you do not enter the action log keywords, the default action is to shut down the port, turn off power to it, and put the port in the PoE error-disabled state. To configure the PoE port to automatically recover from the error-disabled state, use the errdisable detect cause inline-power global configuration command to enable error-disabled detection for the PoE cause and the errdisable recovery cause inline-power interval interval global configuration command to enable the recovery timer for the PoE error-disabled cause.
![]() Caution | If policing is disabled, no action occurs when the powered device consumes more than the maximum power allocation on the port, which could adversely affect the switch. |
You can verify your settings by entering the show power inline police privileged EXEC command.
This example shows how to enable policing of the power consumption and configuring the switch to generate a syslog message on the PoE port on a switch:
Switch(config)# interface gigabitethernet1/0/2 Switch(config-if)# power inline police action log
To display Energy Efficient Ethernet (EEE) information for an interface, use the show eee command in EXEC mode.
show eee { counters | capabilities interface interface-id | status interface interface-id }
counters |
Displays EEE counters. |
capabilities |
Displays EEE capabilities for the specified interface. |
status |
Displays EEE status information for the specified interface. |
interface interface-id |
Specifies the interface for which to display EEE capabilities or status information. |
None
User EXEC
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
You can enable EEE on devices that support low power idle (LPI) mode. Such devices can save power by entering LPI mode during periods of low power utilization. In LPI mode, systems on both ends of the link can save power by shutting down certain services. EEE provides the protocol needed to transition into and out of LPI mode in a way that is transparent to upper layer protocols and applications.
To check if an interface is EEE capable, use the show eee capabilities command. You can enable EEE on an interface that is EEE capable by using the power efficient-ethernet auto interface configuration command.
To view the EEE status, LPI status, and wake error count information for an interface, use the show eee status command.
This is an example of output from the show eee counterscommand:
Switch# show eee counters
ASIC #0
---- ---
LP Active 1G : 0
LP Transitioning 1G : 0
LP Active Tx 100M : 0
LP Transitioning Tx 100M : 0
LP Active Rx 100M : 0
LP Transitioning Rx 100M : 0
ASIC #1
---- ---
LP Active 1G : 0
LP Transitioning 1G : 0
LP Active Tx 100M : 0
LP Transitioning Tx 100M : 0
LP Active Rx 100M : 0
LP Transitioning Rx 100M : 0
This is an example of output from the show eee capabilities command on an interface where EEE is enabled:
Switch# show eee capabilities interface gigabitethernet1/0/1
Gi1/0/1
EEE(efficient-ethernet): yes (100-Tx and 1000T auto)
Link Partner : yes (100-Tx and 1000T auto)
This is an example of output from the show eee capabilities command on an interface where EEE is not enabled:
Switch# show eee capabilities interface gigabitethernet2/0/1
Gi2/0/1
EEE(efficient-ethernet): not enabled
Link Partner : not enabled
This is an example of output from the show eee status command on an interface where EEE is enabled and operational. The table that follows describes the fields in the display.
Switch# show eee status interface gigabitethernet1/0/4
Gi1/0/4 is up
EEE(efficient-ethernet): Operational
Rx LPI Status : Received
Tx LPI Status : Received
This is an example of output from the show eee status command on an interface where EEE operational and the ports are in low power save mode:
Switch# show eee status interface gigabitethernet1/0/3
Gi1/0/3 is up
EEE(efficient-ethernet): Operational
Rx LPI Status : Low Power
Tx LPI Status : Low Power
Wake Error Count : 0
This is an example of output from the show eee status command on an interface where EEE is not enabled because a remote link partner is incompatible with EEE:
Switch# show eee status interface gigabitethernet1/0/3
Gi1/0/3 is down
EEE(efficient-ethernet): Disagreed
Rx LPI Status : None
Tx LPI Status : None
Wake Error Count : 0
To display fan, temperature, redundant power system (RPS) availability, and power information, use the show env command in EXEC mode.
show env { all | fan | power [ all | switch [ stack-member-number ] ] | rps | stack [ stack-member-number ] | temperature [ status ] }
all |
Displays the fan and temperature environmental status and the status of the internal power supplies and the RPS. |
fan |
Displays the switch fan status. |
power |
Displays the internal power status of the active switch. |
all |
(Optional) Displays the status of all the internal power supplies in a standalone switch when the command is entered on the switch, or in all the stack members when the command is entered on the stack master. |
switch |
(Optional) Displays the status of the internal power supplies for each switch in the stack or for the specified switch. This keyword is available only on stacking-capable switches. |
stack-member-number |
(Optional) Number of the stack member for which to display the status of the internal power supplies or the environmental status. The range is 1 to 8. |
rps |
Displays the RPS status. |
stack |
Displays all environmental status for each switch in the stack or for the specified switch. This keyword is available only on stacking-capable switches. |
temperature |
Displays the switch temperature status. |
status |
(Optional) Displays the switch internal temperature (not the external temperature) and the threshold values. |
None
User EXEC
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Use the show env EXEC command to display the information for the switch being accessed—a standalone switch or the stack master. Use this command with the stack and switch keywords to display all information for the stack or for the specified stack member.
If you enter the show env temperature status command, the command output shows the switch temperature state and the threshold level.
You can also use the show env temperature command to display the switch temperature status. The command output shows the green and yellow states as OK and the red state as FAULTY. If you enter the show env all command, the command output is the same as the show env temperature status command output.
This is an example of output from the show env all command:
Switch# show env all
FAN PS-1 is OK
FAN PS-2 is NOT PRESENT
SYSTEM TEMPERATURE is OK
System Temperature Value: 41 Degree Celsius
System Temperature State: GREEN
Yellow Threshold : 66 Degree Celsius
Red Threshold : 76 Degree Celsius
POWER SUPPLY 1A TEMPERATURE: OK
POWER SUPPLY 1B TEMPERATURE: Not Present
SW PID Serial# Status Sys Pwr PoE Pwr Watts
--- ------------------ ---------- --------------- ------- ------- -----
1A PWR-C2-1025WAC DCB1636C003 OK Good Good 250/775
1B Not Present
SW Status RPS Name RPS Serial# RPS Port#
-- ------------- ---------------- ----------- ---------
1 Not Present <>
This is an example of output from the show env fan command:
Switch# show env fan
FAN PS-1 is OK
FAN PS-2 is NOT PRESENT
This is an example of output from the show env power all command on the stack master:
Switch# show env power all
SW PID Serial# Status Sys Pwr PoE Pwr Watts
--- ------------------ ---------- --------------- ------- ------- -----
1A PWR-C2-1025WAC DCB1636C003 OK Good Good 250/775
1B Not Present
This is an example of output from the show env stack command on the stack master:
Switch# show env stack
SWITCH: 1
PS-FAN1 is OK
PS-FAN2 is NOT PRESENT
TEMPERATURE is OK
Temperature Value: 41 Degree Celsius
Temperature State: GREEN
Yellow Threshold : 66 Degree Celsius
Red Threshold : 76 Degree Celsius
POWER is OK
RPS is NOT PRESENT
This example shows how to display the temperature value, state, and the threshold values on a standalone switch. The table describes the temperature states in the command output.
Switch# show env stack
System Temperature Value: 41 Degree Celsius
System Temperature State: GREEN
Yellow Threshold : 66 Degree Celsius
Red Threshold : 76 Degree Celsius
State |
Description |
---|---|
Green |
The switch temperature is in the normal operating range. |
Yellow |
The temperature is in the warning range. You should check the external temperature around the switch. |
Red |
The temperature is in the critical range. The switch might not run properly if the temperature is in this range. |
To display error-disabled detection status, use the show errdisable detect command in EXEC mode.
show errdisable detect
None
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
A gbic-invalid error reason refers to an invalid small form-factor pluggable (SFP) module.
The error-disable reasons in the command output are listed in alphabetical order. The mode column shows how error-disable is configured for each feature.
This is an example of output from the show errdisable detect command:
Switch> show errdisable detect
ErrDisable Reason Detection Mode
----------------- --------- ----
arp-inspection Enabled port
bpduguard Enabled port
channel-misconfig (STP) Enabled port
community-limit Enabled port
dhcp-rate-limit Enabled port
dtp-flap Enabled port
gbic-invalid Enabled port
iif-reg-failure Enabled port
inline-power Enabled port
invalid-policy Enabled port
l2ptguard Enabled port
link-flap Enabled port
loopback Enabled port
lsgroup Enabled port
mac-limit Enabled port
pagp-flap Enabled port
port-mode-failure Enabled port
pppoe-ia-rate-limit Enabled port
psecure-violation Enabled port/vlan
security-violation Enabled port
sfp-config-mismatch Enabled port
sgacl_limitation Enabled port
small-frame Enabled port
storm-control Enabled port
udld Enabled port
vmps Enabled port
psp Enabled port
To display the error-disabled recovery timer information, use the show errdisable recovery command in EXEC mode.
show errdisable recovery
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
A gbic-invalid error-disable reason refers to an invalid small form-factor pluggable (SFP) module interface.
![]() Note | Though visible in the output, the unicast-flood field is not valid. |
This is an example of output from the show errdisable recovery command:
Switch> show errdisable recovery
ErrDisable Reason Timer Status
----------------- --------------
arp-inspection Disabled
bpduguard Disabled
channel-misconfig (STP) Disabled
dhcp-rate-limit Disabled
dtp-flap Disabled
gbic-invalid Disabled
inline-power Disabled
l2ptguard Disabled
link-flap Disabled
mac-limit Disabled
loopback Disabled
pagp-flap Disabled
port-mode-failure Disabled
pppoe-ia-rate-limit Disabled
psecure-violation Disabled
security-violation Disabled
sfp-config-mismatch Disabled
small-frame Disabled
storm-control Disabled
udld Disabled
vmps Disabled
psp Disabled
Timer interval: 300 seconds
Interfaces that will be enabled at the next timeout:
To display the administrative and operational status of all interfaces or for a specified interface, use the show interfaces command in privileged EXEC mode.
show interfaces [ interface-id | vlan vlan-id ] [ accounting | capabilities [ module number ] | debounce | description | etherchannel | flowcontrol | pruning | stats | status [ err-disabled ] | trunk ]
interface-id |
(Optional) ID of the interface. Valid interfaces include physical ports (including type, stack member for stacking-capable switches, module, and port number) and port channels. The port channel range is 1 to 48. |
||
vlan vlan-id |
(Optional) VLAN identification. The range is 1 to 4094. |
||
accounting |
(Optional) Displays accounting information on the interface, including active protocols and input and output packets and octets.
|
||
capabilities |
(Optional) Displays the capabilities of all interfaces or the specified interface, including the features and options that you can configure on the interface. Though visible in the command line help, this option is not available for VLAN IDs. |
||
module number |
(Optional) Displays capabilities of all interfaces on the switch or specified stack member. The range is 1 to 8. This option is not available if you entered a specific interface ID. |
||
debounce |
(Optional) Displays port debounce timer information for an interface. |
||
description |
(Optional) Displays the administrative status and description set for an interface. |
||
etherchannel |
(Optional) Displays interface EtherChannel information. |
||
flowcontrol |
(Optional) Displays interface flow control information. |
||
mtu |
(Optional) Displays the MTU for each interface or for the specified interface. |
||
pruning |
(Optional) Displays trunk VTP pruning information for the interface. |
||
stats |
(Optional) Displays the input and output packets by switching the path for the interface. |
||
status |
(Optional) Displays the status of the interface. A status of unsupported in the Type field means that a non-Cisco small form-factor pluggable (SFP) module is inserted in the module slot. |
||
err-disabled |
(Optional) Displays interfaces in an error-disabled state. |
||
trunk |
(Optional) Displays interface trunk information. If you do not specify an interface, only information for active trunking ports appears. |
![]() Note | Though visible in the command-line help strings, the crb, fair-queue, irb, mac-accounting, precedence, random-detect, and rate-limit keywords are not supported. |
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Use the show interface capabilities module number command to display the capabilities of all interfaces on that switch in the stack. If there is no switch with that module number in the stack, there is no output.
Use the show interfaces interface-id capabilities to display the capabilities of the specified interface.
Use the show interfaces capabilities (with no module number or interface ID) to display the capabilities of all interfaces in the stack.
This is an example of output from the show interfaces command for an interface on stack member 3:
Switch# show interfaces gigabitethernet3/0/2
GigabitEthernet3/0/2 is down, line protocol is down (notconnect)
Hardware is Gigabit Ethernet, address is 2037.064d.4381 (bia 2037.064d.4381)
MTU 1500 bytes, BW 1000000 Kbit/sec, DLY 10 usec,
reliability 255/255, txload 1/255, rxload 1/255
Encapsulation ARPA, loopback not set
Keepalive set (10 sec)
Auto-duplex, Auto-speed, media type is 10/100/1000BaseTX
input flow-control is off, output flow-control is unsupported
ARP type: ARPA, ARP Timeout 04:00:00
Last input never, output never, output hang never
Last clearing of "show interface" counters never
Input queue: 0/2000/0/0 (size/max/drops/flushes); Total output drops: 0
Queueing strategy: fifo
Output queue: 0/40 (size/max)
5 minute input rate 0 bits/sec, 0 packets/sec
5 minute output rate 0 bits/sec, 0 packets/sec
0 packets input, 0 bytes, 0 no buffer
Received 0 broadcasts (0 multicasts)
0 runts, 0 giants, 0 throttles
0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored
0 watchdog, 0 multicast, 0 pause input
0 input packets with dribble condition detected
0 packets output, 0 bytes, 0 underruns
0 output errors, 0 collisions, 1 interface resets
0 unknown protocol drops
0 babbles, 0 late collision, 0 deferred
0 lost carrier, 0 no carrier, 0 pause output
0 output buffer failures, 0 output buffers swapped out
This is an example of output from the show interfaces accounting command:
Switch# show interfaces accounting
Vlan1
Protocol Pkts In Chars In Pkts Out Chars Out
IP 382021 29073978 41157 20408734
ARP 981 58860 179 10740
FastEthernet0
Protocol Pkts In Chars In Pkts Out Chars Out
Other 4 276 0 0
Spanning Tree 41 2132 0 0
CDP 5 2270 10 4318
GigabitEthernet1/0/1
Protocol Pkts In Chars In Pkts Out Chars Out
No traffic sent or received on this interface.
GigabitEthernet1/0/2
Protocol Pkts In Chars In Pkts Out Chars Out
No traffic sent or received on this interface.
GigabitEthernet1/0/3
Protocol Pkts In Chars In Pkts Out Chars Out
Other 0 0 226505 14949330
Spanning Tree 679120 40747200 0 0
CDP 22623 10248219 22656 10670858
DTP 45226 2713560 0 0
GigabitEthernet1/0/4
Protocol Pkts In Chars In Pkts Out Chars Out
No traffic sent or received on this interface.
GigabitEthernet1/0/5
Protocol Pkts In Chars In Pkts Out Chars Out
No traffic sent or received on this interface.
GigabitEthernet1/0/6
Protocol Pkts In Chars In Pkts Out Chars Out
No traffic sent or received on this interface.
<output truncated>
This is an example of output from the show interfaces capabilities command for an interface:
Switch# show interfaces gigabitethernet1/0/1 capabilities
GigabitEthernet1/0/1
Model: WS-C2960XR-24PD-I
Type: 10/100/1000BaseTX
Speed: 10,100,1000,auto
Duplex: half,full,auto
Trunk encap. type: 802.1Q
Trunk mode: on,off,desirable,nonegotiate
Channel: yes
Broadcast suppression: percentage(0-100)
Flowcontrol: rx-(off,on,desired),tx-(none)
Fast Start: yes
QoS scheduling: rx-(not configurable on per port basis),
tx-(4q3t) (3t: Two configurable values and one fixed.)
CoS rewrite: yes
ToS rewrite: yes
UDLD: yes
Inline power: yes
SPAN: source/destination
PortSecure: yes
Dot1x: yes
This is an example of output from the show interfaces interface description command when the interface has been described as Connects to Marketing by using the description interface configuration command:
Switch# show interfaces gigabitethernet1/0/2 description
Interface Status Protocol Description
Gi1/0/2 up down Connects to Marketing
This is an example of output from the show interfaces etherchannel command when port channels are configured on the switch:
This is an example of output from the show interfaces interface-id pruning command when pruning is enabled in the VTP domain:
Switch# show interfaces gigabitethernet1/0/2 pruning
Port Vlans pruned for lack of request by neighbor
Gi1/0/2 3,4
Port Vlans traffic requested of neighbor
Gi1/0/2 1-3
This is an example of output from the show interfaces stats command for a specified VLAN interface:
Switch# show interfaces vlan 1 stats
Switching path Pkts In Chars In Pkts Out Chars Out
Processor 1165354 136205310 570800 91731594
Route cache 0 0 0 0
Total 1165354 136205310 570800 91731594
This is an example of partial output from the show interfaces status command. It displays the status of all interfaces:
Switch# show interfaces status
Port Name Status Vlan Duplex Speed Type
Gi1/0/1 notconnect 1 auto auto 10/100/1000BaseTX
Gi1/0/2 notconnect 1 auto auto 10/100/1000BaseTX
Gi1/0/3 connected 1 a-full a-1000 10/100/1000BaseTX
Gi1/0/4 notconnect 1 auto auto 10/100/1000BaseTX
Gi1/0/5 notconnect 1 auto auto 10/100/1000BaseTX
Gi1/0/6 notconnect 1 auto auto 10/100/1000BaseTX
Gi1/0/7 notconnect 1 auto auto 10/100/1000BaseTX
Gi1/0/8 notconnect 1 auto auto 10/100/1000BaseTX
<output truncated>
This is an example of output from the show interfaces interface-id status command:
Switch# show interfaces gigabitethernet1/0/20 status
Port Name Status Vlan Duplex Speed Type
Gi1/0/20 notconnect 1 auto auto 10/100/1000Ba
seTX
This is an example of output from the show interfaces status err-disabled command. It displays the status of interfaces in the error-disabled state:
Switch# show interfaces status err-disabled
Port Name Status Reason
Gi1/0/2 err-disabled gbic-invalid
Gi2/0/3 err-disabled dtp-flap
This is an example of output from the show interfaces interface-id pruning command:
Switch# show interfaces gigabitethernet1/0/2 pruning
Port Vlans pruned for lack of request by neighbor
This is an example of output from the show interfaces interface-id trunk command. It displays trunking information for the port.
Switch# show interfaces gigabitethernet1/0/1 trunk
Port Mode Encapsulation Status Native vlan
Gi1/0/1 on 802.1q other 10
Port Vlans allowed on trunk
Gi1/0/1 none
Port Vlans allowed and active in management domain
Gi1/0/1 none
Port Vlans in spanning tree forwarding state and not pruned
Gi1/0/1 none
To display various counters for the switch or for a specific interface, use the show interfaces counters command in privileged EXEC mode.
show interfaces [ interface-id ] counters [ errors | etherchannel | module stack-member-number | protocol status | trunk ]
interface-id |
(Optional) ID of the physical interface, including type, stack member (stacking-capable switches only) module, and port number. |
||
errors |
(Optional) Displays error counters. |
||
etherchannel |
(Optional) Displays EtherChannel counters, including octets, broadcast packets, multicast packets, and unicast packets received and sent. |
||
module stack-member-number |
(Optional) Displays counters for the specified stack member. The range is 1 to 8.
|
||
protocol status |
(Optional) Displays the status of protocols enabled on interfaces. |
||
trunk |
(Optional) Displays trunk counters. |
![]() Note | Though visible in the command-line help string, the vlan vlan-id keyword is not supported. |
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
If you do not enter any keywords, all counters for all interfaces are included.
This is an example of partial output from the show interfaces counters command. It displays all counters for the switch.
Switch# show interfaces counters
Port InOctets InUcastPkts InMcastPkts InBcastPkts
Gi1/0/1 0 0 0 0
Gi1/0/2 0 0 0 0
Gi1/0/3 95285341 43115 1178430 1950
Gi1/0/4 0 0 0 0
<output truncated>
This is an example of partial output from the show interfaces counters module command for stack member 2. It displays all counters for the specified switch in the stack.
Switch# show interfaces counters module 2
Port InOctets InUcastPkts InMcastPkts InBcastPkts
Gi1/0/1 520 2 0 0
Gi1/0/2 520 2 0 0
Gi1/0/3 520 2 0 0
Gi1/0/4 520 2 0 0
<output truncated>
This is an example of partial output from the show interfaces counters protocol status command for all interfaces:
Switch# show interfaces counters protocol status
Protocols allocated:
Vlan1: Other, IP
Vlan20: Other, IP, ARP
Vlan30: Other, IP, ARP
Vlan40: Other, IP, ARP
Vlan50: Other, IP, ARP
Vlan60: Other, IP, ARP
Vlan70: Other, IP, ARP
Vlan80: Other, IP, ARP
Vlan90: Other, IP, ARP
Vlan900: Other, IP, ARP
Vlan3000: Other, IP
Vlan3500: Other, IP
GigabitEthernet1/0/1: Other, IP, ARP, CDP
GigabitEthernet1/0/2: Other, IP
GigabitEthernet1/0/3: Other, IP
GigabitEthernet1/0/4: Other, IP
GigabitEthernet1/0/5: Other, IP
GigabitEthernet1/0/6: Other, IP
GigabitEthernet1/0/7: Other, IP
GigabitEthernet1/0/8: Other, IP
GigabitEthernet1/0/9: Other, IP
GigabitEthernet1/0/10: Other, IP, CDP
<output truncated>
This is an example of output from the show interfaces counters trunk command. It displays trunk counters for all interfaces.
Switch# show interfaces counters trunk
Port TrunkFramesTx TrunkFramesRx WrongEncap
Gi1/0/1 0 0 0
Gi1/0/2 0 0 0
Gi1/0/3 80678 0 0
Gi1/0/4 82320 0 0
Gi1/0/5 0 0 0
<output truncated>
To display the administrative and operational status of a switching (nonrouting) port, including port blocking and port protection settings, use the show interfaces switchport command in privileged EXEC mode.
show interfaces [ interface-id ] switchport [ backup [ detail ] | module number ]
interface-id |
(Optional) ID of the interface. Valid interfaces include physical ports (including type, stack member for stacking-capable switches, module, and port number) and port channels. The port channel range is 1 to 48. |
backup |
(Optional) Displays Flex Link backup interface configuration for the specified interface or all interfaces. |
detail |
(Optional) Displays detailed backup information for the specified interface or all interfaces on the switch or the stack. |
module number |
(Optional) Displays switchport configuration of all interfaces on the switch or specified stack member. The range is 1 to 8. This option is not available if you entered a specific interface ID. |
None
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Use the show interface switchport module number command to display the switch port characteristics of all interfaces on that switch in the stack. If there is no switch with that module number in the stack, there is no output.
![]() Note | Private VLANs are not supported in this release, so those fields are not applicable. |
Switch# show interfaces gigabitethernet1/0/1 switchport
Name: Gi1/0/1
Switchport: Enabled
Administrative Mode: trunk
Operational Mode: down
Administrative Trunking Encapsulation: dot1q
Negotiation of Trunking: On
Access Mode VLAN: 1 (default)
Trunking Native Mode VLAN: 10 (VLAN0010)
Administrative Native VLAN tagging: enabled
Voice VLAN: none
Administrative private-vlan host-association: none
Administrative private-vlan mapping: none
Administrative private-vlan trunk native VLAN: none
Administrative private-vlan trunk Native VLAN tagging: enabled
Administrative private-vlan trunk encapsulation: dot1q
Administrative private-vlan trunk normal VLANs: none
Administrative private-vlan trunk associations: none
Administrative private-vlan trunk mappings: none
Operational private-vlan: none
Trunking VLANs Enabled: 11-20
Pruning VLANs Enabled: 2-1001
Capture Mode Disabled
Capture VLANs Allowed: ALL
Protected: false
Unknown unicast blocked: disabled
Unknown multicast blocked: disabled
Appliance trust: none
Field |
Description |
---|---|
Name |
Displays the port name. |
Switchport |
Displays the administrative and operational status of the port. In this display, the port is in switchport mode. |
Administrative Mode Operational Mode |
Displays the administrative and operational modes. |
Administrative Trunking Encapsulation Operational Trunking Encapsulation Negotiation of Trunking |
Displays the administrative and operational encapsulation method and whether trunking negotiation is enabled. |
Access Mode VLAN |
Displays the VLAN ID to which the port is configured. |
Trunking Native Mode VLAN Trunking VLANs Enabled Trunking VLANs Active |
Lists the VLAN ID of the trunk that is in native mode. Lists the allowed VLANs on the trunk. Lists the active VLANs on the trunk. |
Pruning VLANs Enabled |
Lists the VLANs that are pruning-eligible. |
Protected |
Displays whether or not protected port is enabled (True) or disabled (False) on the interface. |
Unknown unicast blocked Unknown multicast blocked |
Displays whether or not unknown multicast and unknown unicast traffic is blocked on the interface. |
Voice VLAN |
Displays the VLAN ID on which voice VLAN is enabled. |
Appliance trust |
Displays the class of service (CoS) setting of the data packets of the IP phone. |
This is an example of output from the show interfaces switchport backup command:
Switch# show interfaces switchport backup Switch Backup Interface Pairs: Active Interface Backup Interface State -------------------------------------------------------------- Gi1/0/1 Gi1/0/2 Active Up/Backup Standby Gi3/0/3 Gi4/0/5 Active Down/Backup Up Po1 Po2 Active Standby/Backup Up
In this example of output from the show interfaces switchport backup command, VLANs 1 to 50, 60, and 100 to 120 are configured on the switch:
Switch(config)# interface gigabitethernet 2/0/6 Switch(config-if)# switchport backup interface gigabitethernet 2/0/8 prefer vlan 60,100-120
When both interfaces are up, Gi2/0/8 forwards traffic for VLANs 60, 100 to 120, and Gi2/0/6 will forward traffic for VLANs 1 to 50.
Switch# show interfaces switchport backup Switch Backup Interface Pairs: Active Interface Backup Interface State ------------------------------------------------------------------------ GigabitEthernet2/0/6 GigabitEthernet2/0/8 Active Up/Backup Up Vlans on Interface Gi 2/0/6: 1-50 Vlans on Interface Gi 2/0/8: 60, 100-120
When a Flex Link interface goes down (LINK_DOWN), VLANs preferred on this interface are moved to the peer interface of the Flex Link pair. In this example, if interface Gi2/0/6 goes down, Gi2/0/8 carries all VLANs of the Flex Link pair.
Switch# show interfaces switchport backup Switch Backup Interface Pairs: Active Interface Backup Interface State ------------------------------------------------------------------------ GigabitEthernet2/0/6 GigabitEthernet2/0/8 Active Down/Backup Up Vlans on Interface Gi 2/0/6: Vlans on Interface Gi 2/0/8: 1-50, 60, 100-120
When a Flex Link interface comes up, VLANs preferred on this interface are blocked on the peer interface and moved to the forwarding state on the interface that has just come up. In this example, if interface Gi2/0/6 comes up, then VLANs preferred on this interface are blocked on the peer interface Gi2/0/8 and forwarded on Gi2/0/6.
Switch# show interfaces switchport backup Switch Backup Interface Pairs: Active Interface Backup Interface State ------------------------------------------------------------------------ GigabitEthernet2/0/6 GigabitEthernet2/0/8 Active Up/Backup Up Vlans on Interface Gi 2/0/6: 1-50 Vlans on Interface Gi 2/0/8: 60, 100-120
To display the physical properties of a small form-factor pluggable (SFP) module interface, use the show interfaces transceiver command in EXEC mode.
show interfaces [ interface-id ] transceiver [ detail | module number | properties | supported-list | threshold-table ]
interface-id |
(Optional) ID of the physical interface, including type, stack member (stacking-capable switches only) module, and port number. |
detail |
(Optional) Displays calibration properties, including high and low numbers and any alarm information for any Digital Optical Monitoring (DoM)-capable transceiver if one is installed in the switch. |
module number |
(Optional) Limits display to interfaces on module on the switch. The range is 1 to 8. This option is not available if you entered a specific interface ID. |
properties |
(Optional) Displays speed, duplex, and inline power settings on an interface. |
supported-list |
(Optional) Lists all supported transceivers. |
threshold-table |
(Optional) Displays alarm and warning threshold table. |
User EXEC
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This is an example of output from the show interfaces interface-id transceiver properties command:
Switch# show interfaces gigabitethernet1/0/50 transceiver properties
Diagnostic Monitoring is not implemented.
Name : Gi1/0/50
Administrative Speed: auto
Administrative Duplex: auto
Administrative Auto-MDIX: on
Administrative Power Inline: N/A
Operational Speed: 1000
Operational Duplex: full
Operational Auto-MDIX: on
Media Type: 10/100/1000BaseTX
This is an example of output from the show interfaces interface-id transceiver detail command:
Switch# show interfaces gigabitethernet1/1/1 transceiver detail
ITU Channel not available (Wavelength not available),
Transceiver is internally calibrated.
mA:milliamperes, dBm:decibels (milliwatts), N/A:not applicable.
++:high alarm, +:high warning, -:low warning, -- :low alarm.
A2D readouts (if they differ), are reported in parentheses.
The threshold values are uncalibrated.
High Alarm High Warn Low Warn Low Alarm
Temperature Threshold Threshold Threshold Threshold
Port (Celsius) (Celsius) (Celsius) (Celsius) (Celsius)
------- ----------------- ---------- --------- --------- ---------
Gi1/1/1 29.9 74.0 70.0 0.0 -4.0
High Alarm High Warn Low Warn Low Alarm
Voltage Threshold Threshold Threshold Threshold
Port (Volts) (Volts) (Volts) (Volts) (Volts)
------- --------------- ---------- --------- --------- ---------
Gi1/1/1 3.28 3.60 3.50 3.10 3.00
Optical High Alarm High Warn Low Warn Low Alarm
Transmit Power Threshold Threshold Threshold Threshold
Port (dBm) (dBm) (dBm) (dBm) (dBm)
------- ----------------- ---------- --------- --------- ---------
Gi1/1/1 1.8 7.9 3.9 0.0 -4.0
Optical High Alarm High Warn Low Warn Low Alarm
Receive Power Threshold Threshold Threshold Threshold
Port (dBm) (dBm) (dBm) (dBm) (dBm)
------- ----------------- ---------- --------- --------- ---------
Gi1/1/1 -23.5 -5.0 -9.0 -28.2 -32.2
This is an example of output from the show interfaces transceiver threshold-table command:
Switch# show interfaces transceiver threshold-table
Optical Tx Optical Rx Temp Laser Bias Voltage
current
------------- ------------- ------ ------------ ---------
DWDM GBIC
Min1 -4.00 -32.00 -4 N/A 4.65
Min2 0.00 -28.00 0 N/A 4.75
Max2 4.00 -9.00 70 N/A 5.25
Max1 7.00 -5.00 74 N/A 5.40
DWDM SFP
Min1 -4.00 -32.00 -4 N/A 3.00
Min2 0.00 -28.00 0 N/A 3.10
Max2 4.00 -9.00 70 N/A 3.50
Max1 8.00 -5.00 74 N/A 3.60
RX only WDM GBIC
Min1 N/A -32.00 -4 N/A 4.65
Min2 N/A -28.30 0 N/A 4.75
Max2 N/A -9.00 70 N/A 5.25
Max1 N/A -5.00 74 N/A 5.40
DWDM XENPAK
Min1 -5.00 -28.00 -4 N/A N/A
Min2 -1.00 -24.00 0 N/A N/A
Max2 3.00 -7.00 70 N/A N/A
Max1 7.00 -3.00 74 N/A N/A
DWDM X2
Min1 -5.00 -28.00 -4 N/A N/A
Min2 -1.00 -24.00 0 N/A N/A
Max2 3.00 -7.00 70 N/A N/A
Max1 7.00 -3.00 74 N/A N/A
DWDM XFP
Min1 -5.00 -28.00 -4 N/A N/A
Min2 -1.00 -24.00 0 N/A N/A
Max2 3.00 -7.00 70 N/A N/A
Max1 7.00 -3.00 74 N/A N/A
CWDM X2
Min1 N/A N/A 0 N/A N/A
Min2 N/A N/A 0 N/A N/A
Max2 N/A N/A 0 N/A N/A
Max1 N/A N/A 0 N/A N/A
<output truncated>
To display the network-policy profiles, use the show network policy profile command in privileged EXEC mode.
show network-policy profile [ profile-number ]
profile-number |
(Optional) Displays the network-policy profile number. If no profile is entered, all network-policy profiles appear. |
None
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This is an example of output from the show network-policy profile command:
Switch# show network-policy profile Network Policy Profile 60 Interface: none
To display the Power over Ethernet (PoE) status for the specified PoE port, the specified stack member, or for all PoE ports in the switch stack, use the show power inline command in EXEC mode.
show power inline [ police | priority ] [ interface-id | module stack-member-number ] [detail]
police |
(Optional) Displays the power policing information about real-time power consumption. |
priority |
(Optional) Displays the power inline port priority for each port. |
interface-id |
(Optional) ID of the physical interface. |
module stack-member-number |
(Optional) Limits the display to ports on the specified stack member. The range is 1 to 8. This keyword is supported only on stacking-capable switches. |
detail |
(Optional) Displays detailed output of the interface or module. |
User EXEC
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
This is an example of output from the show power inline command. The table that follows describes the output fields.
Switch> show power inline
Module Available Used Remaining
(Watts) (Watts) (Watts)
------ --------- -------- ---------
1 n/a n/a n/a
2 n/a n/a n/a
3 1440.0 15.4 1424.6
4 720.0 6.3 713.7
Interface Admin Oper Power Device Class Max
(Watts)
--------- ------ ---------- ------- ------------------- ----- ----
Gi3/0/1 auto off 0.0 n/a n/a 30.0
Gi3/0/2 auto off 0.0 n/a n/a 30.0
Gi3/0/3 auto off 0.0 n/a n/a 30.0
Gi3/0/4 auto off 0.0 n/a n/a 30.0
Gi3/0/5 auto off 0.0 n/a n/a 30.0
Gi3/0/6 auto off 0.0 n/a n/a 30.0
Gi3/0/7 auto off 0.0 n/a n/a 30.0
Gi3/0/8 auto off 0.0 n/a n/a 30.0
Gi3/0/9 auto off 0.0 n/a n/a 30.0
Gi3/0/10 auto off 0.0 n/a n/a 30.0
Gi3/0/11 auto off 0.0 n/a n/a 30.0
Gi3/0/12 auto off 0.0 n/a n/a 30.0
<output truncated>
This is an example of output from the show power inline interface-id command on a switch port:
Switch> show power inline gigabitethernet1/0/1
Interface Admin Oper Power Device Class Max
(Watts)
--------- ------ ---------- ------- ------------------- ----- ----
Gi1/0/1 auto off 0.0 n/a n/a 30.0
Interface AdminPowerMax AdminConsumption
(Watts) (Watts)
---------- --------------- --------------------
Gi1/0/1 30.0 30.0
This is an example of output from the show power inline module switch-number command on stack member 3. The table that follows describes the output fields.
Switch> show power inline module 3
Module Available Used Remaining
(Watts) (Watts) (Watts)
------ --------- -------- ---------
3 865.0 864.0 1.0
Interface Admin Oper Power Device Class Max
(Watts)
--------- ------ ---------- ------- ------------------- ----- ----
Gi3/0/1 auto power-deny 4.0 n/a n/a 15.4
Gi3/0/2 auto off 0.0 n/a n/a 15.4
Gi3/0/3 auto off 0.0 n/a n/a 15.4
Gi3/0/4 auto off 0.0 n/a n/a 15.4
Gi3/0/5 auto off 0.0 n/a n/a 15.4
Gi3/0/6 auto off 0.0 n/a n/a 15.4
Gi3/0/7 auto off 0.0 n/a n/a 15.4
Gi3/0/8 auto off 0.0 n/a n/a 15.4
Gi3/0/9 auto off 0.0 n/a n/a 15.4
Gi3/0/10 auto off 0.0 n/a n/a 15.4
<output truncated>
Field |
Description |
---|---|
Available |
The total amount of configured power1 on the PoE switch in watts (W). |
Used |
The amount of configured power that is allocated to PoE ports in watts. |
Remaining |
The amount of configured power in watts that is not allocated to ports in the system. (Available – Used = Remaining) |
Admin |
Administration mode: auto, off, static. |
Oper |
Operating mode: |
Power |
The maximum amount of power that is allocated to the powered device in watts. This value is the same as the value in the Cutoff Power field in the show power inline police command output. |
Device |
The device type detected: n/a, unknown, Cisco powered-device, IEEE powered-device, or the name from CDP. |
Class |
The IEEE classification: n/a or a value from 0 to 4. |
Max |
The maximum amount of power allocated to the powered device in watts. |
AdminPowerMax |
The maximum amount power allocated to the powered device in watts when the switch polices the real-time power consumption. This value is the same as the Max field value. |
AdminConsumption |
The power consumption of the powered device in watts when the switch polices the real-time power consumption. If policing is disabled, this value is the same as the AdminPowerMax field value. |
This is an example of output from the show power inline police command on a stacking-capable switch:
Switch> show power inline police
Module Available Used Remaining
(Watts) (Watts) (Watts)
------ --------- -------- ---------
1 370.0 0.0 370.0
3 865.0 864.0 1.0
Admin Oper Admin Oper Cutoff Oper
Interface State State Police Police Power Power
--------- ------ ----------- ---------- ---------- ------ ------
Gi1/0/1 auto off none n/a n/a 0.0
Gi1/0/2 auto off log n/a 5.4 0.0
Gi1/0/3 auto off errdisable n/a 5.4 0.0
Gi1/0/4 off off none n/a n/a 0.0
Gi1/0/5 off off log n/a 5.4 0.0
Gi1/0/6 off off errdisable n/a 5.4 0.0
Gi1/0/7 auto off none n/a n/a 0.0
Gi1/0/8 auto off log n/a 5.4 0.0
Gi1/0/9 auto on none n/a n/a 5.1
Gi1/0/10 auto on log ok 5.4 4.2
Gi1/0/11 auto on log log 5.4 5.9
Gi1/0/12 auto on errdisable ok 5.4 4.2
Gi1/0/13 auto errdisable errdisable n/a 5.4 0.0
<output truncated>
In the previous example:
This is an example of output from the show power inline police interface-id command on a standalone switch. The table that follows describes the output fields.
Field |
Description |
||
---|---|---|---|
Available |
The total amount of configured power2 on the switch in watts (W). |
||
Used |
The amount of configured power allocated to PoE ports in watts. |
||
Remaining |
The amount of configured power in watts that is not allocated to ports in the system. (Available – Used = Remaining) |
||
Admin State |
Administration mode: auto, off, static. |
||
Oper State |
Operating mode:
|
||
Admin Police |
Status of the real-time power-consumption policing feature:
|
||
Oper Police |
Policing status:
|
||
Cutoff Power |
The maximum power allocated on the port. When the real-time power consumption is greater than this value, the switch takes the configured policing action. |
||
Oper Power |
The real-time power consumption of the powered device. |
This is an example of output from the show power inline priority command on a standalone switch.
Switch> show power inline priority
Interface Admin Oper Priority
State State
---------- ------ ---------- --------
Gi1/0/1 auto off low
Gi1/0/2 auto off low
Gi1/0/3 auto off low
Gi1/0/4 auto off low
Gi1/0/5 auto off low
Gi1/0/6 auto off low
Gi1/0/7 auto off low
Gi1/0/8 auto off low
Gi1/0/9 auto off low
To display the global maximum transmission unit (MTU) or maximum packet size set for the switch, use the show system mtu command in privileged EXEC mode.
show system mtu
This command has no arguments or keywords.
None
Privileged EXEC
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
For information about the MTU values and the stack configurations that affect the MTU values, see the system mtu command.
This is an example of output from the show system mtu command:
Switch# show system mtu
System MTU size is 1500 bytes
System Jumbo MTU size is 1500 bytes
System Alternate MTU size is 1500 bytes
Routing MTU size is 1500 bytes
To specify the speed of a 10/100/1000/2500/5000 Mb/s port, use the speed command in interface configuration mode. To return to the default value, use the no form of this command.
speed { 10 | 100 | 1000 | 2500 | 5000 | auto [ 10 | 100 | 1000 | 2500 | 5000 ] | nonegotiate }
no speed
10 |
Specifies that the port runs at 10 Mb/s. |
100 |
Specifies that the port runs at 100 Mb/s. |
1000 |
Specifies that the port runs at 1000 Mb/s. This option is valid and visible only on 10/100/1000 Mb/s ports. |
2500 |
Specifies that the port runs at 2500 Mb/s. This option is valid and visible only on mGig supported Ethernet ports. |
5000 |
Specifies that the port runs at 5000 Mb/s. This option is valid and visible only on mGig supported Ethernet ports. |
auto |
Automatically detects the speed the port should run at based on the port at the other end of the link. If you use the 10, 100, 1000, 1000, 2500, 5000 keywords with the auto keyword, the port only autonegotiates at the specified speeds. |
nonegotiate |
Disables autonegotiation, and the port runs at 1000 Mb/s. |
The default is auto.
Interface configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Cisco IOS XE Denali 16.3.1 |
This command was modified. The following keywords were added: 2500, and 5000. These keywords are visible only on mGig supporting devices. |
You cannot configure speed on the 10-Gigabit Ethernet ports.
Except for the 1000BASE-T small form-factor pluggable (SFP) modules, you can configure the speed to not negotiate (nonegotiate) when an SFP module port is connected to a device that does not support autonegotiation.
The new keywords: 2500, and 5000 are visible only on mGig supporting devices.
If the speed is set to auto, the switch negotiates with the device at the other end of the link for the speed setting and then forces the speed setting to the negotiated value. The duplex setting remains as configured on each end of the link, which could result in a duplex setting mismatch.
If both ends of the line support autonegotiation, we highly recommend the default autonegotiation settings. If one interface supports autonegotiation and the other end does not, do use the auto setting on the supported side, but set the duplex and speed on the other side.
![]() Caution | Changing the interface speed and duplex mode configuration might shut down and reenable the interface during the reconfiguration. |
For guidelines on setting the switch speed and duplex parameters, see the “Configuring Interface Characteristics” chapter in the software configuration guide for this release.
You can verify your settings by entering the show interfaces privileged EXEC command.
This example shows how to set speed on a port to 100 Mb/s:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# speed 100
This example shows how to set a port to autonegotiate at only 10 Mb/s:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# speed auto 10
This example shows how to set a port to autonegotiate at only 10 or 100 Mb/s:
Switch(config)# interface gigabitethernet1/0/1 Switch(config-if)# speed auto 10 100
To configure Flex Links, use the switchport backup interface command in interface configuration mode on a Layer 2 interface on the switch stack or on a standalone switch. To remove the Flex Links configuration, use the no form of this command.
switchport backup interface interface-id [ mmu primary vlan vlan-id | multicast fast-convergence | preemption { delay seconds | mode { bandwidth | forced | off } } | prefer vlan vlan-id ]
no switchport backup interface interface-id [ mmu primary vlan | multicast fast-convergence | preemption { delay | mode } | prefer vlan ]
interface-id |
ID of the physical interface. |
mmu |
(Optional) Configures the MAC move update (MMU) for a backup interface pair. |
primary vlan vlan-id |
(Optional) VLAN ID of the primary VLAN. The range is 1 to 4094. |
multicast fast-convergence |
(Optional) Configures multicast fast convergence on the backup interface. |
preemption |
(Optional) Configures a preemption scheme for a backup interface pair. |
delay seconds |
Specifies a preemption delay. The range is 1 to 300 seconds. The default is 35 seconds. |
mode |
Specifies the preemption mode. |
bandwidth |
Specifies that a higher bandwidth interface is preferred. |
forced |
Specifies that an active interface is preferred. |
off |
Specifies that no preemption occurs from backup to active. |
prefer vlan vlan-id |
(Optional) Specifies that VLANs are carried on the backup interfaces of a Flex Link pair. VLAN ID range is 1 to 4094. |
The default is to have no Flex Links defined. The preemption mode is off. No preemption occurs. Preemption delay is set to 35 seconds.
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Flex Links are a pair of interfaces that provide backup to each other. With Flex Links configured, one link acts as the primary interface and forwards traffic, while the other interface is in standby mode, ready to begin forwarding traffic if the primary link shuts down. The interface being configured is referred to as the active link; the specified interface is identified as the backup link. The feature provides an alternative to the Spanning Tree Protocol (STP), allowing users to turn off STP and still retain basic link redundancy.
This command is available only for Layer 2 interfaces.
You can configure only one Flex Link backup link for any active link, and it must be a different interface from the active interface.
An interface can belong to only one Flex Link pair. An interface can be a backup link for only one active link. An active link cannot belong to another Flex Link pair.
A backup link does not have to be the same type (Fast Ethernet or Gigabit Ethernet, for instance) as the active link. However, you should configure both Flex Links with similar characteristics so that there are no loops or changes in behavior if the standby link begins to forward traffic.
Neither of the links can be a port that belongs to an EtherChannel. However, you can configure two port channels (EtherChannel logical interfaces) as Flex Links, and you can configure a port channel and a physical interface as Flex Links, with either the port channel or the physical interface as the active link.
If STP is configured on the switch, Flex Links do not participate in STP in all valid VLANs. If STP is not running, be sure that there are no loops in the configured topology.
This example shows how to configure two interfaces as Flex Links:
Switch# configure terminal Switch(conf)# interface gigabitethernet1/0/1 Switch(conf-if)# switchport backup interface gigabitethernet1/0/2 Switch(conf-if)# end
This example shows how to configure the Gigabit Ethernet interface to always preempt the backup:
Switch# configure terminal Switch(conf)# interface gigabitethernet1/0/1 Switch(conf-if)# switchport backup interface gigabitethernet1/0/2 preemption forced Switch(conf-if)# end
This example shows how to configure the Gigabit Ethernet interface preemption delay time:
Switch# configure terminal Switch(conf)# interface gigabitethernet1/0/1 Switch(conf-if)# switchport backup interface gigabitethernet1/0/2 preemption delay 150 Switch(conf-if)# end
This example shows how to configure the Gigabit Ethernet interface as the MMU primary VLAN:
Switch# configure terminal Switch(conf)# interface gigabitethernet1/0/1 Switch(conf-if)# switchport backup interface gigabitethernet1/0/2 mmu primary vlan 1021 Switch(conf-if)# end
You can verify your setting by entering the show interfaces switchport backup privileged EXEC command.
To prevent unknown multicast or unicast packets from being forwarded, use the switchport block command in interface configuration mode. To allow forwarding unknown multicast or unicast packets, use the no form of this command.
switchport block { multicast | unicast }
no switchport block { multicast | unicast }
multicast |
Specifies that unknown multicast traffic should be blocked.
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unicast |
Specifies that unknown unicast traffic should be blocked. |
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
By default, all traffic with unknown MAC addresses is sent to all ports. You can block unknown multicast or unicast traffic on protected or nonprotected ports. If unknown multicast or unicast traffic is not blocked on a protected port, there could be security issues.
With multicast traffic, the port blocking feature blocks only pure Layer 2 packets. Multicast packets that contain IPv4 or IPv6 information in the header are not blocked.
Blocking unknown multicast or unicast traffic is not automatically enabled on protected ports; you must explicitly configure it.
For more information about blocking packets, see the software configuration guide for this release.
This example shows how to block unknown unicast traffic on an interface:
Switch(config-if)# switchport block unicast
You can verify your setting by entering the show interfaces interface-id switchport privileged EXEC command.
system mtu { bytes | jumbo bytes | routing bytes }
no system mtu
bytes |
Set the system MTU for ports that are set to 10 or 100 Mb/s. The range is 1500 to 1998 bytes. This is the maximum MTU received at 10/100-Mb/s Ethernet switch ports. |
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jumbo bytes |
Set the system jumbo MTU for Gigabit Ethernet ports operating at 1000 Mb/s or greater. The range is 1500 to 9000 bytes. This is the maximum MTU received at the physical port for Gigabit Ethernet ports. |
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routing bytes |
Set the maximum MTU for routed packets. You can also set the maximum MTU to be advertised by the routing protocols that support the configured MTU size. The system routing MTU is the maximum MTU for routed packets and is also the maximum MTU that the switch advertises in routing updates for protocols such as OSPF.
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The default MTU size for all ports is 1500 bytes.
Global configuration
Release | Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
The switch does not support the MTU on a per-interface basis.
When you use this command to change the system MTU or jumbo MTU size, you must reset the switch before the new configuration takes effect. The system MTU setting is saved in the switch environmental variable in NVRAM and becomes effective when the switch reloads. The MTU settings you enter with the system mtu and system mtu jumbo commands are not saved in the switch IOS configuration file, even if you enter the copy running-config startup-config privileged EXEC command. Therefore, if you use TFTP to configure a new switch by using a backup configuration file and want the system MTU to be other than the default, you must explicitly configure the system mtu and system mtu jumbo settings on the new switch and then reload the switch.
Gigabit Ethernet ports operating at 1000 Mb/s are not affected by the system mtu command, and 10/100-Mb/s ports are not affected by thesystem mtu jumbo command.
If you enter a value that is outside the range for the specific type of switch, the value is not accepted.
You can verify your setting by entering the show system mtu privileged EXEC command.
This example shows how to set the global system MTU size to 1600 bytes:
Switch(config)# system mtu 1600 Changes to the system MTU will not take effect until the next reload is done Switch(config)#
This example shows how to set the global system MTU size to 6000 bytes:
Switch(config)# system mtu jumbo 6000 Changes to the system jumbo MTU will not take effect until the next reload is done Switch(config)#
To create a network-policy profile for the voice-signaling application type, use the voice-signaling vlan command in network-policy configuration mode. To delete the policy, use the no form of this command.
voice-signaling vlan { vlan-id [ cos cos-value | dscp dscp-value ] | dot1p [ cos l2-priority | dscp dscp ] | none | untagged }
vlan-id |
(Optional) The VLAN for voice traffic. The range is 1 to 4094. |
cos cos-value |
(Optional) Specifies the Layer 2 priority class of service (CoS) for the configured VLAN. The range is 0 to 7; the default is 5. |
dscp dscp-value |
(Optional) Specifies the differentiated services code point (DSCP) value for the configured VLAN. The range is 0 to 63; the default is 46. |
dot1p |
(Optional) Configures the phone to use IEEE 802.1p priority tagging and to use VLAN 0 (the native VLAN). |
none |
(Optional) Does not instruct the Cisco IP phone about the voice VLAN. The phone uses the configuration from the phone key pad. |
untagged |
(Optional) Configures the phone to send untagged voice traffic. This is the default for the phone. |
No network-policy profiles for the voice-signaling application type are defined.
The default CoS value is 5.
The default DSCP value is 46.
The default tagging mode is untagged.
Network-policy profile configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Use the network-policy profile global configuration command to create a profile and to enter network-policy profile configuration mode.
The voice-signaling application type is for network topologies that require a different policy for voice signaling than for voice media. This application type should not be advertised if all of the same network policies apply as those advertised in the voice policy TLV.
When you are in network-policy profile configuration mode, you can create the profile for voice-signaling by specifying the values for VLAN, class of service (CoS), differentiated services code point (DSCP), and tagging mode.
These profile attributes are contained in the Link Layer Discovery Protocol for Media Endpoint Devices (LLDP-MED) network-policy time-length-value (TLV).
To return to privileged EXEC mode from the network-policy profile configuration mode, enter the exit command.
This example shows how to configure voice-signaling for VLAN 200 with a priority 2 CoS:
Switch(config)# network-policy profile 1 Switch(config-network-policy)# voice-signaling vlan 200 cos 2
This example shows how to configure voice-signaling for VLAN 400 with a DSCP value of 45:
Switch(config)# network-policy profile 1 Switch(config-network-policy)# voice-signaling vlan 400 dscp 45
This example shows how to configure voice-signaling for the native VLAN with priority tagging:
Switch(config-network-policy)# voice-signaling vlan dot1p cos 4
To create a network-policy profile for the voice application type, use the voice vlan command in network-policy configuration mode. To delete the policy, use the no form of this command.
voice vlan { vlan-id [ cos cos-value | dscp dscp-value ] | dot1p [ cos l2-priority | dscp dscp ] | none | untagged }
vlan-id |
(Optional) The VLAN for voice traffic. The range is 1 to 4094. |
cos cos-value |
(Optional) Specifies the Layer 2 priority class of service (CoS) for the configured VLAN. The range is 0 to 7; the default is 5. |
dscp dscp-value |
(Optional) Specifies the differentiated services code point (DSCP) value for the configured VLAN. The range is 0 to 63; the default is 46. |
dot1p |
(Optional) Configures the phone to use IEEE 802.1p priority tagging and to use VLAN 0 (the native VLAN). |
none |
(Optional) Does not instruct the Cisco IP phone about the voice VLAN. The phone uses the configuration from the phone key pad. |
untagged |
(Optional) Configures the phone to send untagged voice traffic. This is the default for the phone. |
No network-policy profiles for the voice application type are defined.
The default CoS value is 5.
The default DSCP value is 46.
The default tagging mode is untagged.
Network-policy profile configuration
Release |
Modification |
---|---|
Cisco IOS 15.0(2)EX1 |
This command was introduced. |
Use the network-policy profile global configuration command to create a profile and to enter network-policy profile configuration mode.
The voice application type is for dedicated IP telephones and similar devices that support interactive voice services. These devices are typically deployed on a separate VLAN for ease of deployment and enhanced security through isolation from data applications.
When you are in network-policy profile configuration mode, you can create the profile for voice by specifying the values for VLAN, class of service (CoS), differentiated services code point (DSCP), and tagging mode.
These profile attributes are contained in the Link Layer Discovery Protocol for Media Endpoint Devices (LLDP-MED) network-policy time-length-value (TLV).
To return to privileged EXEC mode from the network-policy profile configuration mode, enter the exit command.
This example shows how to configure the voice application type for VLAN 100 with a priority 4 CoS:
Switch(config)# network-policy profile 1 Switch(config-network-policy)# voice vlan 100 cos 4
This example shows how to configure the voice application type for VLAN 100 with a DSCP value of 34:
Switch(config)# network-policy profile 1 Switch(config-network-policy)# voice vlan 100 dscp 34
This example shows how to configure the voice application type for the native VLAN with priority tagging:
Switch(config-network-policy)# voice vlan dot1p cos 4