topic Re: MLT between VOSS devices in ExtremeSwitching (VSP/Fabric Engine)

MLT between VOSS devices

ITDept19 — Wed, 25 Jan 2023 05:26:50 GMT

I am after guidance on setting up an MLT between 2 VOSS devices, a Core Switch and a 5420.

Diagram of set up is:

The link between Cores and CabA is multi mode fibre and there’s an Extreme Networks LX GBICs on the uplink ports (1/20 and 1/50).

SPBM is not configured on the Core Switch.

The link between Core2 and CabA-Sw2 has not been connected yet.

The link on CoreA comes up, and stays up, I can see this from running “sh int gig state 1/20”.

The link on the 5420 doesn’t, however there is also nothing in logging file to indicate why.

I’ve confirmed the GBIC is visible on the 5420 with sh plug basic, and I also get a logging message when it’s plugged into port 1/50.

Anything I am missing or doing wrong?

Re: MLT between VOSS devices

Jave — Wed, 25 Jan 2023 14:22:27 GMT

Hi ITDept19,

Just a question before going further: you've mentionned a multi mode fibre, but you are using an LX module, which is intended to be used with SMF fiber. Have you tried to establish link with one SX module ?

Regards.

Re: MLT between VOSS devices

ITDept19 — Wed, 25 Jan 2023 18:34:25 GMT

We only have LX gbics.

We have used LX gbics with multi mode on ERS switches without issues.

The gbic we are using is a 1Gb LX gbic, rather than a 10Gb gbic. I think this may be the issue. I came across https://extremeportal.force.com/ExtrArticleDetail?an=000107496&q=5420 and tried what was suggested without luck.

Re: MLT between VOSS devices

Jave — Thu, 26 Jan 2023 12:58:16 GMT

So you have tried with LR modules without success ?

Re: MLT between VOSS devices

ITDept19 — Thu, 26 Jan 2023 13:49:07 GMT

Yep, I've only got LX modules to test with.
Changing the interfaces to "no auto-negotiate" made no difference.

Unfortunately, I don't have a LC-LC single mode duplex cable to test directly between core and 5420 switch, bypassing the multimode cable run.

Re: MLT between VOSS devices

Miguel-Angel_RO — Mon, 30 Jan 2023 17:43:27 GMT

ITDept19,

The 5420 is quite capricious regarding the auto-nego settings due to a specific chipset on the port.

Did you tried disabling the auto-nego on the ports?

Mig

Re: MLT between VOSS devices

ITDept19 — Tue, 31 Jan 2023 13:26:59 GMT

Yes I disabled auto negotiation on Core port and the 5420 port.
Tomorrow I will be tested with a single mode cable directly between core and 5420 (so bypassing the multimode across the estate).
If it works, I know it's due to the GBIC I'm using.

We've also ordered some SX GBICs, which should be with us next week.

Re: MLT between VOSS devices

EXTR_Paul — Tue, 31 Jan 2023 21:55:44 GMT

out of curiosity. How is SPBm not running on the core when you have a viST configured?

You need to have SPBm up and running on both vIST clusters if you expect SMLT to work.

Also, the simple work around is to just get away with SMLT and do NNIs.