Examples

The following example defines a DHCPv6 guard policy name as policy1, places the router in DHCPv6 guard configuration mode, and enables verification of the advertised prefixes in DHCP reply messages from the configured authorized prefix list:

Router(config)# ipv6 dhcp guard policy policy1
Router(config-dhcp-guard)# match reply prefix-list ipv6pre1

Examples

The following example defines a DHCPv6 guard policy name as policy1, places the router in DHCPv6 guard configuration mode, and enables verification of the advertised DHCP server or relay address in inspected messages from the configured authorized server access list:

Router(config)# ipv6 dhcp guard policy policy1
Router(config-dhcp-guard)# match server access-list ipv6acl1

Examples

The following example specifies the IP address of a NetBIOS name server available to the client:

netbios-name-server 10.12.1.90

Examples

The following example specifies the client’s NetBIOS type as hybrid:

netbios node-type h-node

Examples

The following example shows how to configure 172.16.0.0/12 as the subnetwork number and mask of the DHCP pool named pool1. The IP addresses in pool1 range from 172.16.0.0 to 172.31.255.255.

Router(config)# 
ip dhcp pool pool1
 
Router(dhcp-config)# 
network 172.16.0.0 255.240.0.0

The following example shows how to configure 192.0.2.0/24 as the subnetwork number and mask of the DHCP pool named pool2 and then add the DHCP pool secondary subnet specified by the subnet number and mask 192.0.4.0/30. The IP addresses in pool2 consist of two unconnected subnets: the addresses from 192.0.2.1 to 192.0.2.254 and the addresses from 192.0.4.1 to 192.0.4.2.

Router(config)# 
ip dhcp pool pool2
 
Router(dhcp-config)# 
network 192.0.2.0 255.255.255.0
 
Router(dhcp-config)# 
network 192.0.4.0 255.255.255.252 secondary

Examples

The following example specifies 10.12.1.99 as the IP address of the next server in the boot process:

next-server 10.12.1.99

Examples

The following example shows how to configure DHCP option 19, which specifies whether the client should configure its IP layer for packet forwarding. A value of 0 means disable IP forwarding; a value of 1 means enable IP forwarding. IP forwarding is enabled in the following example.

Router(config)# ip dhcp pool red
Router(dhcp-config)# option 19 hex 01

The following example shows how to configure DHCP option 72, which specifies the World Wide Web servers for DHCP clients. World Wide Web servers 172.16.3.252 and 172.16.3.253 are configured in the following example.

Router(config)# ip dhcp pool red
Router(dhcp-config)# option 72 ip 172.16.3.252 172.16.3.253

Examples

The following example shows how to configure an address pool named pool1 to use DHCP as the subnet allocation protocol with an initial subnet size of 24 and an autogrow subnet size of 24:

ip dhcp pool pool1
  vrf pool1
  origin dhcp subnet size initial /24 autogrow /24
  utilization mark high 80
  utilization mark low 20

The following example shows how to configure the location of the external text file:

ip dhcp pool abcpool
 origin file tftp://10.1.0.1/staticbindingfile

Examples

The following example configures 10.1.1.1/29 as the subnetwork number and mask of the DHCP pool named pool1, adds the DHCP pool secondary subnet specified by the subnet number and mask 10.1.1.17/29, then configures a subnet-specific default router list for that subnet:

Router(config)# dhcp pool pool1
 
Router(config-dhcp)# network 10.1.1.1 255.255.255.248
 
Router(config-dhcp)# network 10.1.1.17 255.255.255.248 secondary
 
Router(config-dhcp-secondary-subnet)# override default-router 10.1.1.100 10.1.1.200
 

Examples

The following example shows how to set the high utilization mark of the secondary subnet to 40 percent of the current subnet size:

Router(config)# ip dhcp pool pool2
 
Router(dhcp-config)# utilization mark high 80 log
 
Router(dhcp-config)# utilization mark low 70 log
 
Router(dhcp-config)# network 192.0.2.0 255.255.255.0
 
Router(dhcp-config)# network 192.0.4.0 255.255.255.252 secondary
 
Router(config-dhcp-subnet-secondary)# override utilization high 40
 
Router(config-dhcp-subnet-secondary)# override utilization low 30

Examples

The following example shows how to set the low utilization mark of the secondary subnet to 30 percent of the current subnet size:

Router(config)# ip dhcp pool pool2
 
Router(dhcp-config)# utilization mark high 80 log
 
Router(dhcp-config)# utilization mark low 70 log
 
Router(dhcp-config)# network 192.0.2.0 255.255.255.0
 
Router(dhcp-config)# network 192.0.4.0 255.255.255.252 secondary
 
Router(config-dhcp-subnet-secondary)# override utilization high 40
 
Router(config-dhcp-subnet-secondary)# override utilization low 30

Examples

The following example defines an DHCPv6 guard policy name as policy1, places the router in DHCPv6 guard configuration mode, and enables verification that the advertised preference is not greater than 254 or less than 2:

Router(config)# ipv6 dhcp guard policy policy1
Router(config-dhcp-guard)# preference min 2
Router(config-dhcp-guard)# preference max 254

Examples

The following example shows the relay information patterns configured for DHCP class 1.

ip dhcp class CLASS1 
 relay agent information 
  relay-information hex 01030a0b0c02050000000123 
  relay-information hex 01030a0b0c02* 
  relay-information hex 01030a0b0c02050000000000 bitmask 0000000000000000000000FF 
ip dhcp class CLASS2 
 relay agent information 

Examples

The following example shows the configured relay agent information patterns. Note that CLASS 2 has no pattern configured and will “match to any” class.

ip dhcp class CLASS1 
 relay agent information 
  relay-information hex 01030a0b0c02050000000123 
  relay-information hex 01030a0b0c02* 
  relay-information hex 01030a0b0c02050000000000 bitmask 0000000000000000000000FF 
ip dhcp class CLASS2 
 relay agent information 

Examples

This example shows how to configure a VLAN as an RSPAN VLAN:

Router(config-vlan)# remote-span
Router(config-vlan)

This example shows how to remove the RSPAN designation:

Router(config-vlan)# no remote-span
Router(config-vlan)

Examples

The following example shows how to restrict address assignments from the DHCP address pool only to the preconfigured reservations:

Router# configure terminal
Router(config)# ip dhcp pool red
Router(dhcp-config)# reserved-only 

Examples

The following is sample output from the show arp command with no optional keywords or arguments specified:

Router# show arp
 
Protocol   Address          Age (min)   Hardware Addr    Type    Interface
Internet   192.0.2.112      120         0000.a710.4baf   ARPA    Ethernet3
AppleTalk  4028.5           29          0000.0c01.0e56   SNAP    Ethernet2
Internet   192.0.2.114      105         0000.a710.859b   ARPA    Ethernet3
AppleTalk  4028.9           -           0000.0c02.a03c   SNAP    Ethernet2
Internet   192.0.2.121      42          0000.a710.68cd   ARPA    Ethernet3
Internet   192.0.2.9        -           0000.3080.6fd4   SNAP    TokenRing0
AppleTalk  4036.9           -           0000.3080.6fd4   SNAP    TokenRing0
Internet   192.0.2.9        -           0000.0c01.7bbd   SNAP    Fddi0

The table below describes the fields shown in the display.

When this command is used to display dynamic ARP entries, the display information includes the time of the last update and the amount of time before the next scheduled refresh is to occur. The following is sample output from the show arp command for the dynamic ARP entry at network address 192.0.2.1:

Router# show arp 192.0.2.1 detail
 
ARP entry for 192.0.2.1, link type IP.
  Alias, last updated 13323 minutes ago.
  Encap type is ARPA, hardware address is 1234.1234.1234, 6 bytes long.
  ARP subblocks:
  * Static ARP Subblock
    Floating entry.
    Entry is complete, attached to GigabitEthernet1/1.
  * IP ARP Adjacency
    Adjacency (for 192.0.2.1 on GigabitEthernet1/1) was installed.

When this command is used to display floating static ARP entries, the display information includes the associated interface, if any.The following is sample output from the show arp command for the floating static ARP entry at network address 192.0.2.2 whose intended interface is down:

Router# show arp 192.0.2.2 detail
 
ARP entry for 192.0.2.2, link type IP.
  Alias, last updated 13327 minutes ago.
  Encap type is ARPA, hardware address is 1234.1234.1234, 6 bytes long.
  ARP subblocks:
  * Static ARP Subblock
    Floating entry.
    Entry is incomplete.
  * IP ARP Adjacency
    Adjacency (for 192.0.2.2 on GigabitEthernet1/1) was withdrawn.

The following is sample detailed output from the show arp command for the Application Alias ARP entry at network address 192.0.2.3:

Router# show arp 192.0.2.3 detail
 
ARP entry for 192.0.2.3, link type IP.
  Application Alias, via Ethernet2/2, last updated 0 minute ago.
  Created by "HSRP".
  Encap type is ARPA, hardware address is 0000.0c07.ac02, 6 bytes long.
  ARP subblocks:
  * Application Alias ARP Subblock
  * HSRP
    ARP Application entry for application HSRP.

The following is sample detailed output from the show arp command for all dynamic ARP entries:

Router# show arp dynamic detail
 
ARP entry for 192.0.2.4, link type IP.
  Dynamic, via Ethernet2/1, last updated 0 minute ago.
  Encap type is ARPA, hardware address is 0000.0000.0014, 6 bytes long.
  ARP subblocks:
  * Dynamic ARP Subblock
    Entry will be refreshed in 0 minute and 1 second.
    It has 1 chance to be refreshed before it is purged.
    Entry is complete.
  * IP ARP Adjacency
    Adjacency (for 192.0.2.4 on Ethernet2/1) was installed.

Examples

The following is sample output from the show hosts command with no parameters specified:

Router# show hosts
 
Default domain is CISCO.COM
Name/address lookup uses domain service
Name servers are 192.0.2.220
Host Flag Age Type Address(es)
EXAMPLE1.CISCO.COM (temp, OK) 1 IP 192.0.2.10
EXAMPLE2.CISCO.COM (temp, OK) 8 IP 192.0.2.50
EXAMPLE3.CISCO.COM (temp, OK) 8 IP 192.0.2.115
EXAMPLE4.CISCO.COM (temp, EX) 8 IP 192.0.2.111
EXAMPLE5.CISCO.COM (temp, EX) 0 IP 192.0.2.27
EXAMPLE6.CISCO.COM (temp, EX) 24 IP 192.0.2.30

The following is sample output from the show hosts command that specifies the VRF vpn101:

Router# show hosts vrf vpn101
 
Default domain is example.com
Domain list: example1.com, example2.com, example3.com
Name/address lookup uses domain service
Name servers are 192.0.2.204, 192.0.2.205, 192.0.2.206
Codes: UN - unknown, EX - expired, OK - OK, ?? - revalidate
       temp - temporary, perm - permanent
       NA - Not Applicable None - Not defined
Host                      Port  Flags      Age Type   Address(es)
user                      None  (perm, OK)  0   IP    192.0.2.001
www.example.com           None  (perm, OK)  0   IP    192.0.2.111
                                                      192.0.2.112

The table below describes the significant fields shown in the display.

Examples

The following is sample output from the show ip aliases command:

Device# show ip aliases 
Address Type             IP Address           Port 
Dynamic                  198.51.100.1
Dynamic 																	198.51.100.22
Dynamic 																	209.165.200.230
Dynamic 																	203.0.113.2
Interface 															203.0.113.200 							SLIP TTY1
Interface 															198.51.100.100 						SLIP TTY1
Interface 															209.165.201.20 						SLIP TTY1
Dynamic 																	209.165.200.226
Interface 															209.165.200.225

Note	Only external IP addresses are displayed in the show ip aliases command output. Internal IP addresses are not displayed.

Examples

The following is sample output from the show ip arp command:

Router# show ip arp
Protocol  Address              Age(min)       Hardware Addr     Type      Interface
Internet  172.16.233.229       -              0000.0c59.f892    ARPA      Ethernet0/0
Internet  172.16.233.218       -              0000.0c07.ac00    ARPA      Ethernet0/0
Internet  172.16.233.19        -              0000.0c63.1300    ARPA      Ethernet0/0
Internet  172.16.233.309       -              0000.0c36.6965    ARPA      Ethernet0/0
Internet  172.16.168.11        -              0000.0c63.1300    ARPA      Ethernet0/0
Internet  172.16.168.254       9              0000.0c36.6965    ARPA      Ethernet0/0 

The table below describes the significant fields shown in the display.

Examples

Examples

IP Address Assignment Example

The following examples show the DHCP binding address parameters, including an IP address, an associated MAC address, a lease expiration date, the type of address assignment that has occurred, and the option 82 suboptions of the remote ID and circuit ID.

The table below describes the significant fields shown in the displays.

Router# show ip dhcp binding 192.0.2.2
IP address          Client-ID/              Lease expiration        Type
                    Hardware address/
                    User name
192.0.2.2           aabb.cc00.0a00          Apr 28 2010 05:00 AM    Automatic
Remote id : 020a00001400006400000000

Examples

Subnet Allocation Example

The following example shows the subnet lease to MAC address mapping, the lease expiration, and the lease type (subnet lease bindings are configured to be automatically created and released by default):

Router# show ip dhcp binding
Bindings from all pools not associated with VRF:
IP address          Client-ID/              Lease expiration        Type
                    Hardware address/
                    User name
192.0.2.2/24        0063.6973.636f.2d64.    Mar 29 2003 04:36 AM    Automatic
                    656d.6574.6572.2d47.
                    4c4f.4241.4c

The table below describes the significant fields shown in the display.

Examples

The following is sample output from the show ip dhcp conflict command, which shows the detection method and detection time for all IP addresses the DHCP server has offered that have conflicts with other devices:

Router# 
show ip dhcp conflict
IP address    Detection method     Detection time         VRF
172.16.1.32   Ping                 Feb 16 1998 12:28 PM   vrf1
172.16.1.64   Gratuitous ARP       Feb 23 1998 08:12 AM   vrf2

The table below describes the fields shown in the display.

The following is sample output from the show ip dhcp conflict vrf command:

Router# 
show ip dhcp conflict vrf vrf1
IP address        Detection method   Detection time          VRF
172.16.1.32       Ping               Feb 15 2009 05:39 AM    vrf1

See the table below for the field description.

Examples

The following example shows all DHCP server database agent information. The table below describes the significant fields shown in the display.

Router# show ip dhcp database
URL       :    ftp://user:password@172.16.4.253/router-dhcp
Read      :    Dec 01 1997 12:01 AM
Written   :    Never
Status    :    Last read succeeded. Bindings have been loaded in RAM.
Delay     :    300 seconds
Timeout   :    300 seconds
Failures  :    0
Successes :    1

Examples

The following is sample output from the show ip dhcp import command:

Router# show ip dhcp import
Address Pool Name:2
Domain Name Server(s): 10.1.1.1
NetBIOS Name Server(s): 10.3.3.3

The following example indicates the address pool name:

Address Pool Name:2

The following example indicates the imported values, which are domain name and NetBIOS name information:

Domain Name Server(s): 10.1.1.1
NetBIOS Name Server(s): 10.3.3.3

Examples

The following example shows DHCP address pool information for an on-demand address pool (ODAP), pool 1. The table below describes the significant fields shown in the display.

Router# show ip dhcp pool 1
Pool 1:
 Utilization mark (high/low)    : 85 / 15
 Subnet size (first/next)       : 24 / 24 (autogrow)
 VRF name                       : abc
 Total addresses                : 28
 Leased addresses               : 11
 Pending event                  : none
 2 subnets are currently in the pool :
 Current index        IP address range           Leased addresses
 10.1.1.12            10.1.1.1 - 10.1.1.14       11
 10.1.1.17            10.1.1.17 - 10.1.1.30      0
 Interface Ethernet0/0 address assignment
   10.1.1.1 255.255.255.248
   10.1.1.17 255.255.255.248 secondary

The following example shows DHCP address pool information for a network pool, pool 2. The table below describes the significant fields shown in the display.

Router# show ip dhcp pool 2
Pool pool2 :
Utilization mark (high/low) : 80 / 70
Subnet size (first/next) : 0 / 0 
Total addresses : 256
Leased addresses : 0
Excluded addresses : 2
Pending event : none
2 subnets are currently in the pool:
Current index   IP address range         Leased/Excluded/Total
10.0.2.1        10.0.2.1 - 10.0.2.254     0     / 1     / 254 
10.0.4.1        10.0.4.1 - 10.0.4.2       0     / 1     / 2 

Examples

The following example displays DHCP server statistics. The table below describes the significant fields in the display.

Router# show ip dhcp server statistics
Memory usage          40392
Address pools         3
Database agents       1
Automatic bindings    190
Manual bindings       1
Expired bindings      3
Malformed messages    0
Secure arp entries    1
Renew messages        0
Message               Received
BOOTREQUEST           12
DHCPDISCOVER          200
DHCPREQUEST           178
DHCPDECLINE           0
DHCPRELEASE           0
DHCPINFORM            0
Message               Sent
BOOTREPLY             12
DHCPOFFER             190
DHCPACK               172
DHCPNAK               6

Examples

This example shows how to display the DHCP snooping configuration:

Router# show ip dhcp snooping
 
Switch DHCP snooping is enabled 
DHCP snooping is configured on following VLANs: 
5 10 
Insertion of option 82 is enabled 
Interface                Trusted     Rate limit (pps) 
--------------------     -------     ---------------- 
FastEthernet6/11         no          10 
FastEthernet6/36         yes         50 

Examples

This example shows how to display the DHCP snooping binding entries for a switch:

Router# show ip dhcp snooping binding
 
MacAddress      IP Address   Lease(seconds)  Type           VLAN   Interface
-----------     -----------  --------------  -------------  -----  --------------
0000.0100.0201  10.0.0.1     600             dhcp-snooping  100    FastEthernet3/1

This example shows how to display an IP address for DHCP snooping binding entries:

Router# show ip dhcp snooping binding 172.16.101.102
MacAddress      IP Address      Lease (seconds)  Type           VLAN   Interface
-----------     -----------     ---------------  -------------  -----  ------------
0000.0100.0201  172.16.101.102  1600             dhcp-snooping  100    FastEthernet3/1

This example shows how to display the MAC address for the DHCP snooping binding entries:

Router# show ip dhcp snooping binding 10.5.5.2 0002.b33f.3d5f
 
MacAddress          IpAddress  Lease(sec)  Type           VLAN  Interface 
------------------  ---------  ----------  -------------  ----  ---------------- 
00:02:B3:3F:3D:5F   10.5.5.2   492         dhcp-snooping  99    FastEthernet6/36 Router# 

This example shows how to display the DHCP snooping binding entries’ MAC address for a specific VLAN:

Router# show ip dhcp snooping binding 10.5.5.2 0002.b33f.3d5f vlan 99
 
MacAddress         IpAddress  Lease(sec)  Type           VLAN  Interface 
-----------------  ---------  ----------  -------------  ----  ---------------- 
00:02:B3:3F:3D:5F  10.5.5.2   479         dhcp-snooping  99    FastEthernet6/36

This example shows how to display the DHCP snooping binding entries on VLAN 100:

Router# show ip dhcp snooping binding vlan 100
MacAddress         IP Address  Lease(seconds)  Type           VLAN  Interface
--------------     ----------  --------------  -------------  ----  --------------
0000.0100.0201     10.0.0.1    1600            dhcp-snooping  100   FastEthernet3/1

This example shows how to display the DHCP snooping binding entries on Fast Ethernet interface 3/1:

Router# show ip dhcp snooping binding interface fastethernet3/1
MacAddress         IP Address  Lease(seconds)  Type           VLAN  Interface
--------------     ----------  --------------  -------------  ----  --------------
0000.0100.0201     10.0.0.1    1600            dhcp-snooping  100   FastEthernet3/1

The table below describes the fields in the show ip dhcp snooping command output.

Examples

This example shows how to display the DHCP snooping database:

Router# show ip dhcp snooping database
Agent URL : 
Write delay Timer : 300 seconds
Abort Timer : 300 seconds
Agent Running : No
Delay Timer Expiry : Not Running
Abort Timer Expiry : Not Running
Last Succeded Time : None
Last Failed Time : None
Last Failed Reason : No failure recorded.
Total Attempts       :        0   Startup Failures :        0
Successful Transfers :        0   Failed Transfers :        0
Successful Reads     :        0   Failed Reads     :        0
Successful Writes    :        0   Failed Writes    :        0
Media Failures       :        0

This example shows how to view additional operating statistics:

Router# show ip dhcp snooping database detail
 
Agent URL : tftp://10.1.1.1/directory/file
Write delay Timer : 300 seconds
Abort Timer : 300 seconds
Agent Running : No
Delay Timer Expiry : 7 (00:00:07)
Abort Timer Expiry : Not Running
Last Succeded Time : None
Last Failed Time : 17:14:25 UTC Sat Jul 7 2001
Last Failed Reason : Unable to access URL.
Total Attempts       :       21   Startup Failures :        0
Successful Transfers :        0   Failed Transfers :       21
Successful Reads     :        0   Failed Reads     :        0
Successful Writes    :        0   Failed Writes    :       21
Media Failures       :        0
First successful access: Read
Last ignored bindings counters :
Binding Collisions    :        0   Expired leases    :        0
Invalid interfaces    :        0   Unsupported vlans :        0
Parse failures        :        0
Last Ignored Time : None
Total ignored bindings counters:
Binding Collisions    :        0   Expired leases    :        0
Invalid interfaces    :        0   Unsupported vlans :        0
Parse failures        :        0

Examples

The following example shows configuration information for interface Gigabit Ethernet 0/3. In this example, the IP flow egress feature is configured on the output side (where packets go out of the interface), and the policy route map named PBRNAME is configured on the input side (where packets come into the interface).

Router# show running-config interface gigabitethernet 0/3
interface GigabitEthernet0/3
 ip address 10.1.1.1 255.255.0.0
 ip flow egress
 ip policy route-map PBRNAME
 duplex auto
 speed auto
 media-type gbic
 negotiation auto
end

The following example shows interface information on Gigabit Ethernet interface 0/3. In this example, MPF is enabled, and both Policy Based Routing (PBR) and NetFlow features are not supported by MPF and are ignored.

Router# show ip interface gigabitethernet 0/3
GigabitEthernet0/3 is up, line protocol is up
  Internet address is 10.1.1.1/16
  Broadcast address is 255.255.255.255
  Address determined by setup command
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Outgoing access list is not set
  Inbound access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP fast switching on the same interface is disabled
  IP Flow switching is disabled
  IP CEF switching is enabled
  IP Feature Fast switching turbo vector
  IP VPN Flow CEF switching turbo vector
  IP multicast fast switching is enabled
  IP multicast distributed fast switching is disabled
  IP route-cache flags are Fast, CEF
  Router Discovery is disabled
  IP output packet accounting is disabled
  IP access violation accounting is disabled
  TCP/IP header compression is disabled
  RTP/IP header compression is disabled
  Policy routing is enabled, using route map PBR
  Network address translation is disabled
  BGP Policy Mapping is disabled
  IP Multi-Processor Forwarding is enabled
     IP Input features, "PBR",
         are not supported by MPF and are IGNORED
     IP Output features, "NetFlow",
         are not supported by MPF and are IGNORED

The following example identifies a downstream VRF instance. In the example, "Downstream VPN Routing/Forwarding "D"" identifies the downstream VRF instance.

Router# show ip interface virtual-access 3
Virtual-Access3 is up, line protocol is up
  Interface is unnumbered. Using address of Loopback2 (10.0.0.8)
  Broadcast address is 255.255.255.255
  Peer address is 10.8.1.1
  MTU is 1492 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP fast switching on the same interface is enabled
  IP Flow switching is disabled
  IP CEF switching is enabled
  IP Feature Fast switching turbo vector
  IP VPN CEF switching turbo vector
  VPN Routing/Forwarding "U"
  Downstream VPN Routing/Forwarding "D"
  IP multicast fast switching is disabled
  IP multicast distributed fast switching is disabled
  IP route-cache flags are Fast, CEF
  Router Discovery is disabled
  IP output packet accounting is disabled
  IP access violation accounting is disabled
  TCP/IP header compression is disabled
  RTP/IP header compression is disabled
  Policy routing is disabled
  Network address translation is disabled
  WCCP Redirect outbound is disabled
  WCCP Redirect inbound is disabled
  WCCP Redirect exclude is disabled
  BGP Policy Mapping is disabled 

The following example shows the information displayed when Unicast RPF drop-rate notification is configured:

Router# show ip interface ethernet 2/3
Ethernet2/3 is up, line protocol is up
  Internet address is 10.0.0.4/16
  Broadcast address is 255.255.255.255
  Address determined by non-volatile memory
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is disabled
  IP Flow switching is disabled
  IP CEF switching is disabled
  IP Null turbo vector
  IP Null turbo vector
  IP multicast fast switching is disabled
  IP multicast distributed fast switching is disabled
  IP route-cache flags are No CEF
  Router Discovery is disabled
  IP output packet accounting is disabled
  IP access violation accounting is disabled
  TCP/IP header compression is disabled
  RTP/IP header compression is disabled
  Probe proxy name replies are disabled
  Policy routing is disabled
  Network address translation is disabled
  WCCP Redirect outbound is disabled
  WCCP Redirect inbound is disabled
  WCCP Redirect exclude is disabled
  BGP Policy Mapping is disabled

Examples

Unicast RPF Information

  Input features: uRPF
  IP verify source reachable-via RX, allow default
   0 verification drops
   0 suppressed verification drops
   0 verification drop-rate
Router#

The following example shows how to display the usability status for a specific VLAN:

Router# show ip interface vlan 1
Vlan1 is up, line protocol is up
  Internet address is 10.0.0.4/24
  Broadcast address is 255.255.255.255
Address determined by non-volatile memory
  MTU is 1500 bytes
  Helper address is not set
  Directed broadcast forwarding is disabled
  Outgoing access list is not set
  Inbound  access list is not set
  Proxy ARP is enabled
  Local Proxy ARP is disabled
  Security level is default
  Split horizon is enabled
  ICMP redirects are always sent
  ICMP unreachables are always sent
  ICMP mask replies are never sent
  IP fast switching is enabled
  IP fast switching on the same interface is disabled
  IP Flow switching is disabled
  IP CEF switching is enabled
  IP Fast switching turbo vector
  IP Normal CEF switching turbo vector
  IP multicast fast switching is enabled
  IP multicast distributed fast switching is disabled
  IP route-cache flags are Fast, CEF
  Router Discovery is disabled
  IP output packet accounting is disabled
  IP access violation accounting is disabled
  TCP/IP header compression is disabled
  RTP/IP header compression is disabled
  Probe proxy name replies are disabled
  Policy routing is disabled
  Network address translation is disabled
  WCCP Redirect outbound is disabled
  WCCP Redirect inbound is disabled
  WCCP Redirect exclude is disabled
  BGP Policy Mapping is disabled
  Sampled Netflow is disabled
  IP multicast multilayer switching is disabled
  Netflow Data Export (hardware) is enabled

The table below describes the significant fields shown in the display.

The following example shows how to display a summary of the usability status information for each interface:

Router# show ip interface brief
Interface     IP-Address     OK?  Method  Status                  Protocol
Ethernet0     10.108.00.5    YES  NVRAM   up                      up      
Ethernet1     unassigned     YES  unset   administratively down   down    
Loopback0     10.108.200.5   YES  NVRAM   up                      up      
Serial0       10.108.100.5   YES  NVRAM   up                      up      
Serial1       10.108.40.5    YES  NVRAM   up                      up      
Serial2       10.108.100.5   YES  manual  up                      up      
Serial3       unassigned     YES  unset   administratively down   down 

The table below describes the significant fields shown in the display.

Examples

The following is sample output from the show ip route dhcpcommand when entered without an address. This command lists all routes added by the DHCP server and relay agent.

Router# show ip route dhcp 
  10.5.5.56/32 is directly connected, ATM0.2
  10.5.5.217/32 is directly connected, ATM0.2

The following is sample output from the show ip route dhcp command when an address is specified. The output shows the details of the address with the server address (who assigned it) and the lease expiration time.

Router# show ip route dhcp 10.5.5.217
 
  10.5.5.217 is directly connected, ATM0.2
    DHCP Server: 10.9.9.10   Lease expires at Nov 08 2001 01:19 PM

The following is sample output from the show ip route vrf vrf-name dhcpcommand when entered without an address:

Router# show ip route vrf abc dhcp
  10.5.5.218/32 is directly connected, ATM0.2

The following is sample output from the show ip route vrf vrf-name dhcpcommand when an address is specified. The output shows the details of the address with the server address (who assigned it) and the lease expiration time.

Router# show ip route vrf red dhcp 10.5.5.218
  10.5.5.218/32 is directly connected, ATM0.2
    DHCP Server: 10.9.9.10   Lease expires at Nov 08 2001 03:15PM

Examples

This example shows the output without entering any keywords:

Router# show ip source binding

MacAddress             IpAddress       Lease(sec) Type          VLAN Interface
------------------     --------------- ---------- ------------- ---- --------------------
00:00:00:0A:00:0B      17.16.0.1        infinite   static        10   FastEthernet6/10
00:00:00:0A:00:0A      17.16.0.2        10000      dhcp-snooping 10   FastEthernet6/11

This example shows how to display the static IP binding entry for a specific IP address:

Router# show ip source binding 17.16.0.1 0000.000A.000B static vlan 10 interface gigabitethernet6/10
MacAddress          IpAddress        Lease(sec)  Type           VLAN  Interface 
------------------  ---------------  ----------  -------------  ----  -------------------- 
00:00:00:0A:00:0B   17.16.0.1         infinite    static         10    FastEthernet6/10 

The table below describes the significant fields in the display.

Examples

This example shows the display when DHCP snooping is enabled on VLANs 10 to 20, the interface has IP source filter mode that is configured as IP, and there is an existing IP address binding 10.0.0.1 on VLAN 10:

Router# show ip verify source interface gigabitethernet6/1
Interface  Filter-type  Filter-mode  IP-address       Mac-address     Vlan
---------  -----------  -----------  ---------------  --------------  ---------
gi6/1      ip           active       10.0.0.1                         10
gi6/1      ip           active       deny-all     			               11-20

This example shows how to display the IP source guard configuration and filters on a specific interface:

Router# show ip verify source interface gigabitethernet6/1
Interface  Filter-type  Filter-mode  IP-address       Mac-address     Vlan
---------  -----------  -----------  ---------------  --------------  ---------
gi6/1      ip           inactive-trust-port

This example shows the display when the interface does not have a VLAN enabled for DHCP snooping:

Router# show ip verify source interface gigabitethernet6/3
Interface  Filter-type  Filter-mode  IP-address       Mac-address     Vlan
---------  -----------  -----------  ---------------  --------------  ---------
gi6/3      ip           inactive-no-snooping-vlan

This example shows the display when the interface has an IP source filter mode that is configured as IP MAC and an existing IP MAC binds 10.0.0.2/aaaa.bbbb.cccc on VLAN 10 and 10.0.0.1/aaaa.bbbb.cccd on VLAN 11:

Router# show ip verify source interface gigabitethernet6/4
Interface  Filter-type  Filter-mode  IP-address       Mac-address     Vlan
---------  -----------  -----------  ---------------  --------------  ---------
gi6/4      ip-mac       active       10.0.0.2         aaaa.bbbb.cccc  10
gi6/4      ip-mac       active       10.0.0.1         aaaa.bbbb.cccd  11
gi6/4      ip-mac       active       deny-all         deny-all        12-20

This example shows the display when the interface has an IP source filter mode that is configured as IP MAC and an existing IP MAC binding 10.0.0.3/aaaa.bbbb.ccce on VLAN 10, but port security is not enabled on the interface:

Router# show ip verify source interface gigabitethernet6/5
Interface  Filter-type  Filter-mode  IP-address       Mac-address     Vlan
---------  -----------  -----------  ---------------  --------------  ---------
gi6/5      ip-mac       active       10.0.0.3         permit-all      10
gi6/5      ip-mac       active       deny-all         permit-all      11-20

This example shows the display when the interface does not have IP source filter mode configured:

Router# show ip verify source interface gigabitethernet6/6
DHCP security is not configured on the interface gi6/6.

This example shows how to display all the interfaces on the switch that have DHCP snooping security enabled:

Router# show ip verify source
 
Interface  Filter-type  Filter-mode  IP-address       Mac-address     Vlan
---------  -----------  -----------  ---------------  --------------  ---------
gi6/1      ip           active       10.0.0.1                         10
gi6/1      ip           active       deny-all                         11-20
gi6/2      ip           inactive-trust-port
gi6/3      ip           inactive-no-snooping-vlan
gi6/4      ip-mac       active       10.0.0.2         aaaa.bbbb.cccc  10
gi6/4      ip-mac       active       11.0.0.1         aaaa.bbbb.cccd  11
gi6/4      ip-mac       active       deny-all         deny-all        12-20
gi6/5      ip-mac       active       10.0.0.3         permit-all      10
gi6/5      ip-mac       active       deny-all         permit-all      11-20
Router# 

This example shows how to display all the interfaces on the switch that have DHCP snooping security enabled:

Router# show ip verify source interface gi5/0/0 efp_id 10
Interface  Filter-type  Filter-mode  IP-address       Mac-address        Vlan        EFP ID
---------    -----------    -----------      ---------------     -----------------     ----------  ----------
Gi5/0/0    ip-mac       active          123.1.1.1        00:0A:00:0A:00:0A  100        10  
Gi5/0/0    ip-mac       active          123.1.1.2        00:0A:00:0A:00:0B  100        20  
Gi5/0/0    ip-mac       active          123.1.1.3        00:0A:00:0A:00:0C  100        30  

Examples

The following is a sample output from the show ipv6 dhcp conflict command. This command shows the pool and prefix values for DHCP conflicts.:

Router# show ipv6 dhcp conflict
Pool 350, prefix 2001:0DB8:1005::/48
	    2001:0DB8:1005::10

Examples

The following example defines a DHCPv6 guard policy name as policy1, places the router in DHCPv6 guard configuration mode, and sets the port to trusted:

Router(config)# ipv6 dhcp guard policy policy1
Router(config-dhcp-guard)# trusted-port

Examples

The following example sets the high utilization mark to 80 percent of the current pool size:

utilization mark high 80

The following pool configuration using the log keyword option generates a system message:

! ip dhcp pool abc 
utilization mark high 30 log 
utilization mark low 25 log 
network 10.1.1.0 255.255.255.248 
! 

The following system message is generated when the second IP address is allocated from the pool:

00:02:01: %DHCPD-6-HIGH_UTIL: Pool "abc" is in high utilization state (2 addresses used out of 6). Threshold set at 30%.

The following system message is generated when one of the two allocated IP addresses is returned to the pool:

00:02:58: %DHCPD-6-LOW_UTIL: Pool "abc" is in low utilization state (1 addresses used out of 6). Threshold set at 25%. 

Examples

The following example sets the low utilization mark to 20 percent of the current pool size:

utilization mark low 20