The Default-Router [Ip Address] Cisco command

Syntax: default-router [ip-address]

Usage: The default-router command is used to configure a default router for a Cisco router. The default router is the router that the router will use to forward packets that are not destined for any of the directly connected networks.

Effect: The default-router command adds the specified IP address to the routing table as a default route. This means that the router will send any packets that are not destined for any of the directly connected networks to the specified router.

Equipment: The default-router command can be used on all Cisco routers.

Configuration: To configure a default router, enter the following command in configuration mode:

default-router [ip-address]

For example, to configure the router to use the router with the IP address 10.0.0.1 as the default router, enter the following command:

default-router 10.0.0.1

Verification: To verify that the default router has been configured correctly, enter the following command in privileged EXEC mode:

show ip route

The output of the show ip route command will include a route to the default router. The route to the default router will have a destination of 0.0.0.0 and a next hop of the IP address of the default router.

Troubleshooting: If you are having problems configuring a default router, check the following:

• Make sure that the IP address of the default router is correct.
• Make sure that the default router is reachable from the router.
• Make sure that the default route is not being overridden by a more specific route.

default-router [ip address] Usage Examples

Thedefault-router [ip address]command specifies the IP address of the default next-hop router to use for forwarding packets outside of the local network. This command can be used on the following interfaces:

• Ethernet
• ATM
• Frame Relay
• PPP
• Serial
• ISDN

The following are examples of thedefault-router [ip address]command:

• To specify the default router IP address on Ethernet interfaceEthernet0/1:

  interface Ethernet0/1
  default-router 192.168.1.254
  

• To specify the default router IP address on ATM interfaceATM0/1:

  interface ATM0/1
  default-router 172.16.1.254
  

• To specify the default router IP address on Frame Relay interfaceFrame-Relay0/1:

  interface Frame-Relay0/1
  default-router 10.0.0.254
  

• To specify the default router IP address on PPP interfacePPP0:

  interface PPP0
  default-router 203.0.113.1
  

• To specify the default router IP address on Serial interfaceSerial0/0:

  interface Serial0/0
  default-router 192.0.2.254
  

• To specify the default router IP address on ISDN interfaceISDN0:

  interface ISDN0
  default-router 192.168.2.254