Best Path learning issues

[Augman Tod]

HI

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My users in vlan 2 getting disconnected frequently. SW1 is the root bridge for vlan 2 but th packet from R1 flows through SW2 to the users in vlan 2. There is no root bridge misconfig. when i do "show ip ospf route" it shows path through SW2 is the best but still it shows there is another route through SW1. But it considers SW2 as best path. I checked path costs are same. how do i troubleshoot this one?

[Georg Pauwen]

Hello,

hard to say, as this could be a spanning tree related problem as well. Post the configs of the L3 switches and the routers...

[chrihussey]

Agree with Georg that the disconnect problems may be a spanning tree issue.

By default, OSPF will send traffic across four equal cost paths. So if R1 is showing routes to VLAN 2 via both SW1 and SW2, chances are it sends to one for a while then the other. A lot depends on the amount of traffic. Wherever the asterisk is is the route that is being used.

You could force the traffic to SW1 by simply adjusting the OSPF link costs.

[Julio E. Moisa]

Hi

Is possible to share:

- the config of the routers and the switches
- Show ip route from each device
- show ip ospf neighbors from the switches.

Thank you in advance