N7K OSPF Path Selection

[tobin_jim]

Any ideas why an Nexus 7K would be choosing an OSPF external route over an Interarea route?

The N7K has two OSPF routing processes and is getting the route via each process (this is expected). It seems to be choosing the path with the lowest cost first rather than using the normal OSPF path selection process of Interarea over External route before looking at the cost.

172.26.135.1/32, ubest/mbest: 1/0
    *via 172.25.249.2, Eth3/2, [110/265], 00:11:26, ospf-1, type-1, tag 100,
     via 10.253.255.1, Vlan999, [110/301], 00:11:22, ospf-100, inter

[Mark Malone · Accepted solution]

HI

When you run multiple ospf processes the route which installs itself in the OSPF RIB will be the one that makes it to the global RIB table just the way it is

If you want the other route to win shut down the winning route for a minute by shutting the interface its from

[Vasilii Mikhailovskii · Accepted solution]

Hello.

NX unlike IOS does not check any route attributes (across different routing processes) but AD and metric (for the same protocol).

This comes from internal architecture limitations and there are no plans to change this.