3Com 2500 Enter destination IP address Enter subnet mask 255.255.0.0, Enter gateway IP address

9-12 CHAPTER 9: ADMINISTERING IP ROUTING

Example:

Enter destination IP address: 158.101.4.0

Enter subnet mask [255.255.0.0]: 255.255.255.0

Enter gateway IP address: 158.101.2.8

Removing a Route

Top-Level Menu
system
ethernet	interface
fddi	➧route	display
atm	arp	static
bridge	atmArpServer	➧remove
➧ip	multicast	flush
ipx	udpHelper	default
appletalk	routing	noDefault
snmp	icmpRouterDiscovery
analyzer	rip
script	ping
logout	statistics

Flushing a Route

Top-Level Menu
system
	interface
ethernet
	➧route	display
fddi	arp	static
atm
	atmArpServer	remove
bridge
	multicast	➧flush
➧ip
	udpHelper	default
ipx
	routing	noDefault
appletalk
	icmpRouterDiscovery
snmp
	rip
analyzer
	ping
script
	statistics
logout

To remove a route:

1From the top level of the Administration Console, enter:

ip route remove

2Enter the destination IP address of the route.

3Enter the subnet mask of the route.

The route is immediately deleted from the routing table.

Flushing deletes all learned routes from the routing table.

To flush all learned routes, from the top level of the Administration Console, enter:

ip route flush

All learned routes are immediately deleted from the routing table.

Setting the Default If you define a default route, the system uses it to forward packets that do Route not match any other routing table entry. A system can learn a default route

using RIP, or you can configure a default route statically.

If a system’s routing table does not contain a default route — either statically configured or learned using RIP — then it cannot forward a packet that does not match any other routing table entry. If this occurs, then the module drops the packet and sends an ICMP “destination unreachable” message to the host that sent the packet.