topic Uplink configuration between EXOS stack 5320 and VOSS cluster in ExtremeSwitching (EXOS/Switch Engine)

Uplink configuration between EXOS stack 5320 and VOSS cluster

Tamaya — Wed, 13 Aug 2025 19:10:36 GMT

Hello,

Can someone please confirm whether the uplink configuration between a VOSS cluster and an EXOS 5320 stack is correct? (See attached diagram.)

For EXOS-to-EXOS, how should the uplinks be configured when they connect to a 5520 cluster used for VPEX?

During a production test of the VOSS cluster ↔ EXOS connection, we saw Centreon alerts indicating that some switches became unreachable, which forced us to disconnect the link. Our environment is large and mixed, with VOSS, EXOS, and ERS switches (SPB, MLT, SLT…).

Could this be related to the configuration spanning tree settings? If so, what are the best practices for spanning tree in this scenario?
Also, what troubleshooting steps would you recommend to isolate the issue?

Thanks for your help!

Re: Uplink configuration between EXOS stack 5320 and VOSS cluster

Christoph — Thu, 14 Aug 2025 14:24:36 GMT

Hi,

one thing I saw in your diagram: You had set LACP timer to short interval on VOSS.
The timer should be the same on both ends of the link.
So on EXOS "configure sharing 1:53 lacp timeout short" has to be set, too.
Or leave defaults on both ends.

Regards
Christoph

Re: Uplink configuration between EXOS stack 5320 and VOSS cluster

Tamaya — Thu, 14 Aug 2025 23:18:34 GMT

Hi Christoph,

Thanks for your message. I have read that in a Fabric Attach environment, there is no need to configure uplinks on the EXOS side, as they are handled automatically by the fabric.
https://documentation.extremenetworks.com/exos_32.5/GUID-F140CBF4-6E25-4DA7-92EC-DD5B645E1218.shtml

Regards,