Riverstone Networks WICT1-12 - Manual (Page 218)

14-2 Riverstone Networks RS Switch Router User Guide Release 8.0
OSPF Multipath OSPF Configuration Guide
• Route Redistribution: Routes learned via RIP, BGP, or any other sources can be redistributed into
OSPF. OSPF routes can be redistributed into RIP or BGP. For information on Route Redistribution,
refer to
Chapter 18, "Routing Policy Configuration" .
14.1 OSPF MULTIPATH
The RS also supports OSPF and static Multi-path. If multiple equal-cost OSPF or static routes have been defined for
any destination, then the RS “discovers” and uses all of them. The RS will automatically learn up to four equal-cost
OSPF or static routes and retain them in its forwarding information base (FIB). The forwarding module then installs
flows for these destinations in a round-robin fashion.
14.2 CONFIGURING OSPF
To configure OSPF on the RS, perform the following tasks:
• Set the router ID.
• Enable OSPF
• Create the OSPF area
• Add interfaces to the area
• If necessary, configure virtual links
• Optionally, configure parameters at the global, area, and/or interface level.
14.3 SETTING THE ROUTER ID
The router ID uniquely identifies the RS. To set the router ID to be used by OSPF, enter the following command in
Configure mode.
If you do not explicitly specify the router ID, then an ID is chosen implicitly by the RS. A secondary address on the
loopback interface (the primary address being 127.0.0.1) is the most preferred candidate for selection as the RS’ router
ID. If there are no secondary addresses on the loopback interface, then the default router ID is set to the address of the
first interface that is in the up state that the RS encounters (except the interface en0, which is the Control Module’s
interface). The address of a non point-to-point interface is preferred over the local address of a point-to-point interface.
If the router ID is implicitly chosen to be the address of a non-loopback interface, and if that interface were to go down,
then the router ID is changed. When the router ID changes, an OSPF router has to flush all its LSAs from the routing
domain.
If you explicitly specify a router ID, then it would not change, even if all interfaces were to go down.
Set the RS’ router ID.
ip-router global set router-id
<hostname-or-IPaddr>