Avaya ERS 8600 series, Руководство по настройке

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AS external routes
With OSPF, the following routes are AS external (ASE) routes:
• a route to a destination outside the AS
• a static route
• a default route
• a directly connected network not running OSPF
OSPF virtual links
On an OSPF network, an Avaya Ethernet Routing Switch 8800/8600 that is an ABR must
connect directly to the backbone. If no physical connection is available, you can configure a
virtual link automatically or manually.
An automatic virtual link provides redundancy support for critical network connections.
Automatic virtual linking creates virtual paths for vital traffic paths in your OSPF network. The
virtual link is available to maintain connectivity if a network connection fails, such as when an
interface cable connected to the backbone (either directly or indirectly) disconnects from the
switch.
Specifying automatic virtual linking ensures that a link is created to another router. When you
specify automatic virtual linking, the feature is always ready to create a virtual link. Create
manual virtual links if automatic virtual linking uses more resources than you want to use. With
virtual links, you can conserve resources, while having specific control over virtual link
placement in your OSPF configuration.
Figure 8: Virtual link between ABRs through a transit area on page 46 shows how to configure
a virtual link between the ABR in area 2.2.2.2 and the ABR in area 0.0.0.0.
Routing
Configuration — IPv6 Routing November 2010 45