Extreme Networks Summit1 - Manual (Page 133)

S UMMIT S WITCH I NSTALLATION AND U SER G UIDE 9-3
O VERVIEW OF IP U NICAST R OUTING
P OPULATING THE R OUTING T ABLE
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.
D YNAMIC R OUTES
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.
S TATIC R OUTES
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