• November 29, 2020, 05:46:37 PM
Welcome, Guest. Please login or register. Registration is free.
Did you miss your activation email?

Author Topic: STP not enabled on Trunks  (Read 1907 times)

0 Members and 1 Guest are viewing this topic.

Offline rayacain90

  • Rookie
  • **
  • Posts: 1
STP not enabled on Trunks
« on: February 25, 2016, 02:32:51 PM »

New to the forum as well as to the Avaya world.
The site that I work at runs Avaya 5520 ERS. It is maintained by on off site organization of ours.
The problem is we have been having a LOT of ARP broadcasts going through the network lately. Looking at the configs I had noticed that STP is enabled on the access ports but it is disabled on the single line trunks as well as the 2 MLT we have.
I talked to our NOSC that has, hopefully, more Avaya experience than I do and they said that STP isn't used on the switches. It uses an Avaya Proprietary form of STP that you don't put on a trunk.

Can anyone explain to me how STP works on these switches when it comes to trunks and if they are accurate in what they are saying. I have a good amount of STP knowledge on Cisco devices just not Avaya.


Offline Johan Witters

  • Sr. Member
  • ****
  • Posts: 252
    • BKM Networks
Re: STP not enabled on Trunks
« Reply #1 on: February 26, 2016, 05:54:36 AM »

Nortel/Avaya states that you disable STP/RSTP/MSTP on MLT's only if they are configured in a SMLT (Split multilink trunk) environment. In this scenario you have 2 clustered "core" switches, and your edge is connected to these 2 cluster nodes. By configuring the uplinks on the cluster side, it provides a an alternative process to prevent loops, and STP needs to be disabled to prevent STP from blocking the redundant links...

If you are not running SMLT, you still need to enable spanning tree on your MLT's. It will not block ports within the MLT, but it would not detect a loop when you would connect an extra cable.
Kind regards,

Johan Witters

Network Engineer