Extreme 3804 User Guide

S

UMMIT

 S

WITCH

 I

NSTALLATION

 

AND

 U

SER

 G

UIDE

9-3

O

VERVIEW

 

OF

 IP U

NICAST

 R

OUTING

The Summit maintains an IP routing table for both network routes and host routes. The 
table is populated from the following sources:

Dynamically, by way of routing protocol packets or ICMP redirects exchanged with 
other routers

Statically, by way of routes entered by the administrator

Default routes, configured by the administrator

Locally, by way of interface addresses assigned to the Summit

By other static routes, as configured by the administrator

If you define a default route, and subsequently delete the VLAN on the subnet 
associated with the default route, the invalid default route entry remains. You 
must manually delete the configured default route. 

Dynamic routes are typically learned by way of RIP or OSPF. Routers that use RIP or 
OSPF exchange information in their routing tables in the form of advertisements. Using 
dynamic routes, the routing table contains only networks that are reachable. 

Dynamic routes are aged out of the table when an update for the network is not 
received for a period of time, as determined by the routing protocol.

Static routes are manually entered into the routing table. Static routes are used to reach 
networks not advertised by routers. You can configure up to 64 static unicast routes on 
the Summit. 

Static routes can also be used for security reasons, to control which routes you want 
advertised by the router. You can decide if you want all static routes to be advertised, 
using one of the following commands:

[enable | disable] rip exportstatic

[enable | disable] ospf exportstatic

The default setting is enabled. Static routes are never aged out of the routing table.

Summit.bk : 9ROUT.FM  Page 3  Thursday, June 18, 1998  9:27 AM