cGVRP
The Compact Generic Attribute Registration Protocol (GARP) VLAN Registration Protocol (GVRP) (cGVRP) feature reduces CPU time for the transmission of 4094 VLAN states on a port.
Finding Feature Information
Your software release may not support all the features documented in this module. For the latest feature information and caveats, see the release notes for your platform and software release. To find information about the features documented in this module, and to see a list of the releases in which each feature is supported, see the "Feature Information for cGVRP" section.
Use Cisco Feature Navigator to find information about platform support and Cisco IOS and Catalyst OS software image support. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Contents
•
Troubleshooting the cGVRP Configuration
•Configuration Examples for cGVRP
•Feature Information for cGVRP
Restrictions for cGVRP
•A non-Cisco device can only interoperate with a Cisco device through .1Q trunks.
•VLAN Mapping is not supported with GVRP.
•cGVRP and Connectivity Fault Management (CFM) can coexist but if the line card (LC) or supervisor does not have enough mac-match registers to support both protocols, the cGVRP ports on those LCs are put in error disabled state. To use Layer 2 functionality, disable cGVRP on those ports and configure shut/no shut.
•cGVRP functionality applies only to interfaces configured for Layer 2 (switchport) functionality.
•Native VLAN Tagging causes frames sent to the native VLAN of the .1Q trunk ports to be encapsulated with .1Q tags. Problems may arise with other GVRP participants on the LAN because they may not be able to admit tagged GVRP PDUs. Caution must be exercised if both features are enabled at the same time.
•802.1X authentication and authorization takes place after the port becomes link-up and before the Dynamic Trunking Protocol (DTP) negotiations start prior to GVRP running on the port.
•Port Security works independently from GVRP and it may be limited to the number of other GVRP participants on a LAN that a GVRP enabled port on a device can communicate with.
•GVRPs cannot be configured and used on a sub-interface.
•GVRP and UniDirectional Link Routing (UDLR) should not be enabled on the same interface because UDLR limits frames in one direction on the port and GVRP is a two way communication protocol.
•Additional memory is required to store GARP/GVRP configurations and states per GVRP enabled port, but it can be dynamically allocated on demand.
•GARP Multicast Registration Protocol (GMRP) is not supported.
Information About cGVRP
•GVRP Interoperability with VTP and VTP Pruning
•GVRP Interoperability with Other Software Features and Protocols
GARP/GVRP Definition
GVRP enables automatic configuration of switches in a VLAN network allowing network devices to dynamically exchange VLAN configuration information with other devices. GVRP is based on GARP which defines procedures for registering and deregistering attributes with each other. It eliminates unnecessary network traffic by preventing attempts to transmit information to unregistered users.
GVRP is defined in IEEE 802.1Q.
cGVRP Overview
GVRP is a protocol that requires extensive CPU time in order to transmit all 4094 VLAN states on a port. In Compact mode only one PDU is sent and it includes the states of all the 4094 VLANs on a port.
VLAN pruning can be accomplished faster by running in a special mode, Fast Compact Mode, and on point-to-point links.
In Compact GVRP a GVRP PDU may be sent out the port if the port is in forwarding state in a spanning tree instance. GVRP PDUs must be transmitted in the native VLAN of .1Q trunks.
GVRP Interoperability with VTP and VTP Pruning
VTP Pruning is an extension of VTP. It has its own Join message that can be exchanged with VTP PDUs. VTP PDUs can be transmitted on both .1Q trunks and ISL trunks. A VTP capable device is in either one of the three VTP modes: Server, Client, or Transparent.
When VTP Pruning and GVRP are both enabled globally, VTP Pruning is run on ISL trunks, and GVRP is run on .1Q trunks.
Compact GVRP has two modes: Slow Compact Mode, and Fast Compact Mode. A port can be in Fast Compact Mode if it has one GVRP enabled peer on the same LAN segment, and the peer is capable of operating in Compact Mode. A port is in Slow Compact Mode if there are multiple GVRP participants on the same LAN segment operating in Compact Mode.
GVRP Interoperability with Other Software Features and Protocols
This section briefly describes GVRP interoperability with the following software features and protocols.
STP
Spanning Tree Protocol (STP) may run in one of the three STP modes: Multiple Spanning Tree(MST), Per VLAN Spanning Tree (PVST), or Rapid PVST. An STP mode range causes the forwarding ports to leave the forwarding state as STP has to reconverge. This may cause GVRP to have its own topology change as Join messages my be received on some new ports and Leave timers may expire on some others.
DTP
DTP (DDSN Transfer Protocol) negotiates the port mode (trunk versus non-trunk) and the trunk encapsulation type between two DTP enabled ports. After negotiation DTP may set the port to either ISL trunk, or .1Q trunk, or non-trunk. DTP negotiation occurs after ports become link-up and before they become forwarding in spanning trees. If GVRP is administratively enabled on a port and the device, it should be initialized after the port is negotiated to be a .1Q trunk.
VTP
VTP (Virtual Terminal Protocol) version 3 expands the range of VLANs that can be created and removed via VTP. VTP Pruning is available for VLAN 1 through 1005 only.
EtherChannel
When multiple .1Q trunk ports are grouped by either Port Aggregation Protocol (PAgP) or Link Aggregation Control Protocol (LACP) to become an EtherChannel, the EtherChannel can be configured as a GVRP participant. The physical ports in the EtherChannel cannot be GVRP participants by themselves. Since an EtherChannel is treated like one virtual port by STP, the GVRP application can learn the STP state change of the EtherChannel just like any physical port. The EtherChannel, not the physical ports in the channel, constitutes the GARP Information Propagation (GIP) context.
High Availability
High Availability (HA) is a redundancy feature in IOS. On platforms that support HA and State SwitchOver (SSO), many features and protocols my resume working in a couple of seconds after the system encounters a failure such as a crash of the active supervisor in a Catalyst 7600 switch. GVRP needs to be configured to enable user configurations, and protocol states should be synched to a standby system. If there is a failure of the active system, the GVRP in the standby system which now becomes active, has all the up-to-date VLAN registration information.
How to Configure cGVRP
•Configuring Compact GVRP (Required)
•Disabling mac-learning on VLANs (Optional)
•Enabling a Dynamic VLAN (Optional)
Configuring Compact GVRP
To configure compact GVRP, complete the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. gvrp global
4. gvrp timer join timer-value
5. gvrp registration normal
6. end
DETAILED STEPS
Disabling mac-learning on VLANs
To disable mac-learning on VLANs, complete the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. gvrp mac-learning auto
4. end
DETAILED STEPS
Enabling a Dynamic VLAN
To enable a dynamic VLAN, complete the following steps.
SUMMARY STEPS
1. enable
2. configure terminal
3. gvrp vlan create
4. end
DETAILED STEPS
Troubleshooting the cGVRP Configuration
To troubleshoot the cGVRP configuration, use one or more of the commands listed below.
Use the show gvrp summary command and the show gvrp interface command to display configuration information and interface state information. Use the debug gvrp command to enable all or a limited set of output messages related to an interface.
SUMMARY STEPS
1. enable
2. show gvrp summary
3. show gvrp interface
4. debug gvrp
5. clear gvrp statistics
6. end
DETAILED STEPS
Configuration Examples for cGVRP
•Disabling mac-learning on VLANs
•Enabling a Dynamic VLAN: Example
•Verifying CE Port Configurations: Examples
•Verifying Disabled mac-learning on VLANs: Example
•Verifying Dynamic VLAN: Example
Configuring cGVRP: Example
The following example shows how to configure compact GVRP.
Router> enable
Router# configure terminal
Router(config)# gvrp global
Router(config)# gvrp timer join 1000
Router(config)# gvrp registration normal
Router(config)# end
Disabling mac-learning on VLANs: Example
The following example shows how to disable mac-learning on VLANs configured with cGVRP.
Router> enable
Router# configure terminal
Router(config)# gvrp mac-learning auto
Router(config)# end
Enabling a Dynamic VLAN: Example
The following example shows how to configure a dynamic VLAN.
Router> enable
Router# configure terminal
Router(config)# gvrp vlan create
Router(config)# end
Verifying CE Port Configurations: Examples
This section contains examples that can be used to verify the CE port configurations. It contains the following examples:
•Verifying CE Ports Configured as Access Ports: Example
•Verifying CE Ports Configured as ISL Ports: Example
•Verifying CE Ports Configured in Fixed Registration Mode: Example
•Verifying CE Ports Configured in Forbidden Registration Mode: Example
•Verifying CE Ports Configured with a .1Q Trunk: Example
The examples provide sample output of the show running-config command, the show grvp summary command, and the show grvp interface command. The output of these commands is based on the following topology:
•CE (customer edge) 1 port on a gigabitethernet 3/15 interface
•Router 1 with a gigabitethernet 3/1 interface
•A .1Q trunk across a gigabitethernet 3/1 interface
•Router 2 with a gigabitethernet 2/15 interface
•CE 2 port
Verifying CE Ports Configured as Access Ports: Example
The following is sample output of the show running-config interface command, the show grvp summary, and the show grvp interface command. In this configuration the CE ports are configured as access ports.
Router1# show running-config interface gigabitethernet 3/15
Building configuration...
Current configuration : 129 bytes
!
interface GigabitEthernet3/15
switchport
switchport access vlan 2
switchport mode access
spanning-tree portfast trunk
end
Router1# show running-config interface gigabitethernet 3/1
Building configuration...
Current configuration : 109 bytes
!
interface GigabitEthernet3/1
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
end
Router2# show running-config interface gigabitethernet 12/15
Building configuration...
Current configuration : 168 bytes
!
interface GigabitEthernet12/15
switchport
switchport access vlan 2
switchport trunk encapsulation dot1q
switchport mode access
spanning-tree portfast trunk
end
Router2# show running-config interface gigabitethernet 3/1
Building configuration...
Current configuration : 144 bytes
!
interface GigabitEthernet3/1
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport backup interface Gi4/1
end
Router1# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : disabled
VLANs created via GVRP : none
MAC learning auto provision : disabled
Learning disabled on VLANs : none
Router1# show gvrp interface
Port Status Mode Registrar State
Gi3/1 on fastcompact normal
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/1 200 600 10000
Port Vlans Declared
Gi3/1 2
Port Vlans Registered
Gi3/1 2
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/1 2
Router2# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : disabled
VLANs created via GVRP : none
MAC learning auto provision : disabled
Learning disabled on VLANs : none
Router2# show gvrp interface
Port Status Mode Registrar State
Gi3/1 on fastcompact normal
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/1 200 600 10000
Port Vlans Declared
Gi3/1 2
Port Vlans Registered
Gi3/1 2
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/1 2
Verifying CE Ports Configured as ISL Ports: Example
The following is sample output of the show running-config interface command, the show grvp summary, the show grvp interface command, and the show vlan summary command. In this configuration the CE ports are configured as ISL ports.
Router1# show running-config interface gigabitethernet 3/15
Building configuration...
Current configuration : 138 bytes
!
interface GigabitEthernet3/15
switchport
switchport trunk encapsulation isl
switchport mode trunk
spanning-tree portfast trunk
end
Router1# show running-config interface gigabitethernet 3/1
Building configuration...
Current configuration : 109 bytes
!
interface GigabitEthernet3/1
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
end
Router2# show running-config interface gigabitethernet 12/15
Building configuration...
Current configuration : 139 bytes
!
interface GigabitEthernet12/15
switchport
switchport trunk encapsulation isl
switchport mode trunk
spanning-tree portfast trunk
end
Router2# show running-config interface gigabitethernet 3/1
Building configuration...
Current configuration : 144 bytes
!
interface GigabitEthernet3/1
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
switchport backup interface Gi4/1
end
Router1# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : disabled
VLANs created via GVRP : none
MAC learning auto provision : disabled
Learning disabled on VLANs : none
Router1# show gvrp interface
Port Status Mode Registrar State
Gi3/1 on fastcompact normal
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/1 200 600 10000
Port Vlans Declared
Gi3/1 1-10
Port Vlans Registered
Gi3/1 1-2
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/1 1-2
Router1# show vlan summary
Number of existing VLANs : 14
Number of existing VTP VLANs : 14
Number of existing extended VLANs : 0
Router2# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : disabled
VLANs created via GVRP : none
MAC learning auto provision : disabled
Learning disabled on VLANs : none
Router2# show gvrp interface
Port Status Mode Registrar State
Gi3/1 on fastcompact normal
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/1 200 600 10000
Port Vlans Declared
Gi3/1 1-2
Port Vlans Registered
Gi3/1 1-10
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/1 1-2
Router2# show vlan summary
Number of existing VLANs : 6
Number of existing VTP VLANs : 6
Number of existing extended VLANs : 0
Verifying CE Ports Configured in Fixed Registration Mode: Example
The following is sample output of the show running-config interface command and the show grvp interface command. In this configuration the CE ports are configured in fixed registration mode.
Router1# show running-config interface gigabitethernet 3/15
Building configuration...
Current configuration : 165 bytes
!
interface GigabitEthernet3/15
gvrp registration fixed
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
spanning-tree portfast trunk
end
Router1# show gvrp interface gigabitethernet 3/15
Port Status Mode Registrar State
Gi3/15 on fastcompact fixed
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/15 200 600 10000
Port Vlans Declared
Gi3/15 1-2
Port Vlans Registered
Gi3/15 1-4094
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/15 1-10
Verifying CE Ports Configured in Forbidden Registration Mode: Example
The following is sample output of the show running-config interface command and the show grvp interface command. In this configuration the CE ports are configured in forbidden registration mode.
Router1# show running-config interface gigabitethernet 3/15
Building configuration...
Current configuration : 169 bytes
!
interface GigabitEthernet3/15
gvrp registration forbidden
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
spanning-tree portfast trunk
end
Router1# show gvrp interface gigabitethernet 3/15
Port Status Mode Registrar State
Gi3/15 on fastcompact forbidden
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/15 200 600 10000
Port Vlans Declared
Gi3/15 1-2
Port Vlans Registered
Gi3/15 none
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/15 none
Verifying CE Ports Configured with a .1Q Trunk: Example
The following is sample output of the show running-config interface command, the show grvp summary, and the show grvp interface command. In this configuration the CE ports are configured with a .1Q trunk.
Router1# show running-config interface gigabitethernet 3/15
Building configuration...
Current configuration : 165 bytes
!
interface GigabitEthernet3/15
gvrp registration fixed
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
spanning-tree portfast trunk
end
Router2# show running-config interface gigabitethernet 12/15
Building configuration...
Current configuration : 166 bytes
!
interface GigabitEthernet12/15
gvrp registration fixed
switchport
switchport trunk encapsulation dot1q
switchport mode trunk
spanning-tree portfast trunk
end
Router1# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : disabled
VLANs created via GVRP : none
MAC learning auto provision : disabled
Learning disabled on VLANs : none
Router1# show gvrp interface
Port Status Mode Registrar State
Gi3/1 on fastcompact normal
Gi3/15 on fastcompact fixed
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/1 200 600 10000
Gi3/15 200 600 10000
Port Vlans Declared
Gi3/1 1-10
Gi3/15 1-2
Port Vlans Registered
Gi3/1 1-2
Gi3/15 1-4094
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/1 1-2
Gi12/15 1-10
Router2# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : disabled
VLANs created via GVRP : none
MAC learning auto provision : disabled
Learning disabled on VLANs : none
Router2# show gvrp interface
Port Status Mode Registrar State
Gi3/1 on fastcompact normal
Gi12/15 on fastcompact fixed
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/1 200 600 10000
Gi12/15 200 600 10000
Port Vlans Declared
Gi3/1 1-2
Gi12/15 1-2
Port Vlans Registered
Gi3/1 1-10
Gi12/15 1-4094
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/1 1-2
Gi12/15 1-2
Verifying cGVRP: Example
The following is sample output from the show grvp summary command. Use the show grvp summary command to verify the compact GVRP configuration.
Router# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : disabled
VLANs created via GVRP : none
MAC learning auto provision : disabled
Learning disabled on VLANS : none
Verifying Disabled mac-learning on VLANs: Example
The following is sample output from the show gvrp summary command and the show gvrp interface command. Use these two commands to verify that mac-learning has been disabled.
Router# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : enabled
VLANs created via GVRP : 2-200
MAC learning auto provision : enabled
Learning disabled on VLANs : 1-200
Router# show gvrp interface
Port Status Mode Registrar State
Gi3/15 on fastcompact normal
Gi4/1 on fastcompact normal
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/15 200 600 10000
Gi4/1 200 600 10000
Port Vlans Declared
Gi3/15 1-200
Gi4/1 none
Port Vlans Registered
Gi3/15 none
Gi4/1 1-200
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/15 none
Gi4/1 1-200
Router# show mac- dy
Legend: * - primary entry
age - seconds since last seen
n/a - not available
vlan mac address type learn age ports
------+----------------+--------+-----+----------+--------------------------
No entries present.
Verifying Dynamic VLAN: Example
The following is sample output from the show gvrp summary command and the show gvrp interface command. Use these two commands to verify the dynamic VLAN configuration.
Router# show gvrp summary
GVRP global state : enabled
GVRP VLAN creation : enabled
VLANs created via GVRP : 2-200
MAC learning auto provision : disabled
Learning disabled on VLANs : none
Router# show gvrp interface
Port Status Mode Registrar State
Gi3/15 on fastcompact normal
Gi4/1 on fastcompact normal
Port Transmit Timeout Leave Timeout Leaveall Timeout
Gi3/15 200 600 10000
Gi4/1 200 600 10000
Port Vlans Declared
Gi3/15 1-200
Gi4/1 none
Port Vlans Registered
Gi3/15 none
Gi4/1 1-200
Port Vlans Registered and in Spanning Tree Forwarding State
Gi3/15 none
Gi4/1 1-200
Additional References
Related Documents
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IP LAN switching commands: complete command syntax, command mode, defaults, usage guidelines, and examples |
Standards
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No new or modified standards are supported by this feature, and support for existing standards has not been modified by this feature. |
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MIBs
RFCs
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No new or modified RFCs are supported by this feature, and support for existing standards has not been modified by this feature. |
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Technical Assistance
Feature Information for cGVRP
Table 1 lists the release history for this feature.
Not all commands may be available in your Cisco IOS software release. For release information about a specific command, see the command reference documentation.
Use Cisco Feature Navigator to find information about platform support and software image support. Cisco Feature Navigator enables you to determine which Cisco IOS and Catalyst OS software images support a specific software release, feature set, or platform. To access Cisco Feature Navigator, go to http://www.cisco.com/go/cfn. An account on Cisco.com is not required.
Note Table 1 lists only the Cisco IOS software release that introduced support for a given feature in a given Cisco IOS software release train. Unless noted otherwise, subsequent releases of that Cisco IOS software release train also support that feature.
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