1

If I configure a second interface on the router to connect to the same network as the other, will it cause spanning-tree to reconverge when I plug it into the switch?

E.g. existing interface is 10.1.1.1/24, and I need to configure and add 10.1.1.5/24. I don't want to wait until after-hours to avoid the network blip, but I will have to if STP is going to recalculate and reconverge.

  • (I need to make some changes for the VoIP service-module which includes giving the router another IP on the same subnet. Other methods of configuring it, e.g. on a loopback adapter or in a new subnet have made it difficult to route.) – ewall Aug 27 '09 at 15:35
2

It all depends if you've configured your two interfaces to bridge and to enable STP. If it is not, then it won't make your STP re-converge, as your interfaces will no broadcast STP announcements. Adding an additional IP address will not make any difference as it's a different layer.

  • Ah, yes... that makes sense now. To the switch, it just looks like I plugged in another device. And this router is not doing any switching nor participating in STP, of course. – ewall Aug 27 '09 at 17:50
2

A router does not participate in STP. A "layer 3 switch" can though. But unless you're adding physical ports or adding/removing vlans STP won't even notice.

1

i don't think it will, unless your router is also your switch, STP to my knowledge is Layer 2, ip is layer 3

0

If the interfaces have different IP's there there shouldn't be a problem. That being said I still wouldn't do this during business hours.

  • Good point... but the time crunch may make that decision for me. – ewall Aug 27 '09 at 17:51

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.