3Com 3500 manual Icmp router discovery can be set on a per-interface basis

ip interface icmpRouterDiscovery 415

ip interface icmpRouterDiscovery

✓3500

✓9000

9400

3900

9300

For CoreBuilder 9000: Applies to Layer 3 switching modules only.

Enables or disables Internet Control Message Protocol (ICMP) router discovery, which enables hosts that are attached to multicast or broadcast networks to discover the IP addresses of their neighboring routers and determine which router to use for a default gateway.

Valid Minimum Abbreviation

ip i icmpro

Important Considerations

■ICMP router discovery can be set on a per-interface basis.

■When you enable the state for an interface, the system prompts you for a preference. (See RFC 1256.) By default, this preference level is 0. Use the preference to control the use of certain routers as the default router. The host uses the router with the highest preference level.

■An appropriately configured end station can locate one or more routers on the LAN to which it is attached. The end station then automatically installs a default route to each of the routers that are running Internet Control Message Protocol (ICMP) router discovery. You do not need to manually configure a default route. ICMP redirect messages subsequently channel the IP traffic to the correct router.

■You can configure only certain end stations to work with the ICMP router discovery protocol. See the documentation for your workstation to determine whether you can configure it to work with this protocol.

■You can configure and display three timers for ICMP router discovery on the CoreBuilder 3500:

■Maximum advertisement interval — The maximum time interval between advertisements.

■Minimum advertisement interval — The minimum time interval between advertisements.

■Advertisement holdtime — The length of time that advertisements are held valid.