Switch User Manual

32 An Introduction to IP Routing Protocols

Virtual link diagram

Note: Stub or NSSA areas cannot be transit areas.

A virtual link can be created manually or automatically.

Manual virtual link creation can conserve resources and provide speciﬁc

control of virtual link placement in the OSPF conﬁguration.

To add a virtual link manually, conﬁgure both endpoint ABRs with a neighbor

router ID and transit area ID. You can conﬁgure up to 16 virtual links.

Note: You can modify parameters for manually added virtual links.

To accept automatic virtual link creation, enable automatic virtual link on

both endpoint ABRs (the default value is disabled). Automatic virtual links

are removed when the transit area is deleted, auto virtual link is disabled,

or the router is no longer an ABR.

Note: Auto-created virtual links use default settings that cannot be

modiﬁed.

Example Conﬁguration

Consider the following situation:

Nortel Ethernet Routing Switch 5500 Series

Conﬁguration-IP Routing Protocols

NN47200-503 03.01 Standard

5.1 27 August 2007