topic Re: 40GbE backbone - is this possible using the VSP 8404C chassis? in ExtremeSwitching (VSP/Fabric Engine)

40GbE backbone - is this possible using the VSP 8404C chassis?

ExtremeNewbie — Wed, 14 Jan 2026 10:03:18 GMT

Hello Community,

I have a pair of the VSP 8404C chassis currently linked at 10GbE I believe. I have managed to get hold of 2 x 8418XSQ 16-port 10 Gigabit Ethernet SFP+ and 2-port 40 Gigabit Ethernet QSFP+ Combo ESM cards and have a free slot in each switch to add this card to.

We currently use OM3 and OM4 fibre between the 2 VSP 8404C switches.

My question is, if this is possible, how would I link the 2x 8418XSQ cards so the backbone to the card runs at 40GbE using the 2x 40GbE port on each card?

Is this even possible?

Many thanks and apologies if this posted in the wrong section.

Re: 40GbE backbone - is this possible using the VSP 8404C chassis?

Shaja — Wed, 14 Jan 2026 11:19:46 GMT

The fiber OM3/4 MM fiber is about 100m reach for 40/100GE

Take care about the distance between those 2 switches..

Re: 40GbE backbone - is this possible using the VSP 8404C chassis?

ExtremeNewbie — Wed, 14 Jan 2026 11:30:30 GMT

@Shaja Thanks for the reply, yes, I know about the distances. I would like someone to advise on how to set this up. I know I will probably have to use a Single Mode fibre cable for the link unless someone knows otherwise. Currently, the distance between the 2 switches is about 160M.

Thanks,

Re: 40GbE backbone - is this possible using the VSP 8404C chassis?

WillyHe — Wed, 14 Jan 2026 13:39:26 GMT

Hello,

Remarks.

Is a throughput of 80Gbps needed?

Meaning, when it regards an SMLT cluster setup to wich all (or most) connected devices/switches are LAG to SMLT up-linked then there is no real need for 80G connectivity.
When it are e.g. local "core" switches in different buildings then this high throughput can be usefully.

Re: 40GbE backbone - is this possible using the VSP 8404C chassis?

ExtremeNewbie — Wed, 14 Jan 2026 14:21:31 GMT

@WillyHe thanks for the reply. We are currently maxing out on our 10GbE connection at times hence looking at a 40GbE connection.

Thanks,

Re: 40GbE backbone - is this possible using the VSP 8404C chassis?

Shaja — Fri, 16 Jan 2026 12:25:32 GMT

Hi @ExtremeNewbie

I will prefer to use 10GE X not single 40GE +you will not have distance problem with the older MM fiber.

Somehow If you are going to invest in SM fiber cable that probably much more expensive than that VSP 8404C.

VSP 8404C end of sale was in 2023 +5 that mean end of life in about 2028.

That is not very long time IMHO

Best regards

Shay