Management interface connectivity using only Loopback interface on ospf

[Starfish]

Hello,

I have a C3650 switch (call it switch A), it connects to another C3650 (switch B)which is configured as layer 3 with ospf on it.

Switch A connects to 3 layer 2 4500 switches, nothing else is configured on this switch A except for loopback address.

Can I just configure ospf on this switch A and will it become ospf neighbour to switch B then?

Will this help me with management access to this switch A?

Do I need to configure anything else to bring management connectivity

[Richard Burts]

Joseph

I appreciate your comments and recognize your disclaimer that you were rehashing some points already made. I did not interpret it as an attempt to correct something that I had written.

I am not clear whether we agree or do not agree about the optimum solution. My perspective is that the SVI is required for routing to work and that the SVI is sufficient for providing management access to the switch. The loopback is not required and adding the loopback adds complexity and I do not see that adding the loopback adds value (what does the loopback provide that the SVI does not provide). So I believe that the simpler solution is the optimum solution.

HTH

Rick

[Joseph W. Doherty]

Rick, I find nothing wrong with your logic.

The reason I cannot agree or disagree whether forgoing the loopback makes sense is because of what we don't know.

The OP does mention having OSPF on another L3 switch. Perhaps they already use loopbacks, on OSPF routers, for management purposes. (The fact OP notes a loopback was set on this switch, not using routing, also makes one wonder.) So, perhaps, using a loopback, although I agree would not be optimal technically, it might be optimally policy wise.

Or, perhaps multiple paths exist or will be added to this device. If those paths become routed paths, then a (routed) loopback begins to make technical sense.

That said, from the little we do know, I do agree with you a routed loopback adds complexity and the simpler solution of not having it, would be more optimal.

[Starfish]

Thank you everyone for your support and suggestions.

I brought up connection using SVI and then configured ospf.

This community is amazing, thanks so much :)

[Richard Burts]

You are welcome. This discussion has been interesting and I am glad that you have found our suggestions helpful. In this discussion, as in many network discussions, there was more than one way to understand the issue and more than one way to provide a solution. Thank you for confirming that you chose the solution of configuring SVI and running OSPF on it.

You are right that this forum is amazing. I hope to see you continue to be active in it.

HTH

Rick