FabricPath move multidestination tree root

[Olle Johansson]

Hi!

I have googled and searched the forums hi and low and I have not found the answer. If someone already has answered this please let me know.

We have a network with 8x N5k switches (4 pairs). 2 of them acts as spine and the rest are leaf’s with fexs.

My problem is that in the beginning multidestination root tree priority where not set so the newest leaf pair are tree root.

When change the priority values on spine switches, will it disrupt the traffic or will the root change smoothly?

 Thankful for all help!

Regards Olle

[Rajeshkumar Gatti · Accepted solution]

Hi,

There will be disruption for BUM traffic (broadcast, unknown unicast, multicast)  traversing the tree for which the new leaf is the root (FTAG 1 or FTAG 2) assuming default single FP topology.

I cannot quantify the exact seconds of the loss but from my own experience in the field it has been less than 30 seconds. Unicast traffic should not be affected since the forwarding of traffic is based on the ECMP feature of L2 ISIS.

-Raj

[Olle Johansson]

Thank for that answer!

It really helped me in my planing