OSPF Virtual Links – The Details

A little over a year ago I wrote an article on Cisco.com on how to take the OSPF topology table and turn it into a diagram. The goal of that document was to really show how each LSA interacts and creates a network. What has been missing from that document is how Virtual Links work in this context.

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Administrative Distance – Only Half the Story

In the image below you can see how each protocol presents itself to the routing table (RIB). The RIB uses AD to determine which route to install. But what about how the protocol chooses which route to present to the RIB?


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