Showing results for 
Search instead for 
Did you mean: 

EXOS MLAG and bonded S8s

EXOS MLAG and bonded S8s

Extreme Employee
Hello Extreme Hub,

I have a questions regarding EXOS MLAG and bonded S8s

1st here is the scenario:

I have a customer with bonded S8s that function essentially as a collapsed core (Distribution/Core and some direct server connections)
S8-Alpha is building 'A' and S8-Bravo is in 'Building B'
There is a Data Center in Building A and a Data Center in Building B, each Data Center server is single homed to its buildings S8. Also each buildings IDFs are also single homed to its local buildings S8.

The customer is going to be increasing their fiber infrastructure between building A and building B with the goal of dual homing the Data Center servers and some of the IDFs.
The customer also plans to add some EXOS x690s to move the Data Center servers off of the S8s. So all of the servers would connect to local MLAG'd x690s, and the x690s would then uplink to each S8 (local and remote) using the new fiber infrastructure.

My question is, are there any issues connected MLAG'd x690s to bonded S8's with regards to STP or any other loop prevention protocols? (XLRP)
Am i correct in saying, that from the perspective of the x690s, the ports facing the servers need to be set up as MLAG and the ports facing the bonded S8s need to be set up as MLAG ? (otherwise, the ISC between the x690s would not block looped traffic from the S8s ?)

Should each x690s connect to more than one blade per S8 chassis ?

The x690s would be set up as L2, VRRP and routing would still be handled by the S8s.

I am not familiar with S8 bonding and I am newer to EXOS... I just want to make sure I am not creating a problem with this design.



Contributor II

I had posted an answer before, but it was lost in the platform troubles. 😞

Anyway, connecting two X690 via MLAG to an S-Series VSB should work without problems. You should probably consider a few things:
  • always use LACP
  • manually configure the LACP MAC used by MLAG (for stability)
  • disable STP on the MLAG ports and the S-Series LAG and physical ports of the LAG
  • remove all egress VLANs from the S-Series physical ports of the LAG
  • configure VLANs only on the LAG of the S-Series
Regarding the S-Series you migt want to look at EOS: Basic Switch Layer 2 Configuration Best Practices and minimum feature recommendations. Regarding the combination of S-Series and EXOS MLAG you might want to look at How to configure MLAG with EXOS core switches to EOS edge switch (that looks at the different direction, i.e. connecting to an EXOS core, but the principles should be similar).


22.6 has a crash so I've gone back to 22.5 (not that I use MLAG or MSTP)

I think MSTP over MLAG ports is a really important feature, and I plan to try it out in the future, but have not yet tested it. Has anybody tried it out, or does anybody use it production already?

interesting... i would also not recommend it lol