topic Will MLAG "break" the ring when non-EXOS switches are used? in ExtremeSwitching (EXOS/Switch Engine)

Will MLAG "break" the ring when non-EXOS switches are used?

kaare_t — Tue, 12 Nov 2019 01:17:10 GMT

Hi all,

Today I have a setup in our factory floor, with a stack of 2 X440-G2 switches in the distribution room, and ISW-series switches in on the production floor, like the setup below:

Present

For added redundancy I would like to add another stack similar to the one I have, and then connect “from the other side” to the ISW line:

Future

I’m a bit in the dark regarding MLAG, since it would basically work if I had a single ISW connected to a port in each stack. Will it work when I have two ISW’s, or will this be a typical ring configuration? Would it be possible to setup ring on the ISW ports, and use MLAG between the stacks?

Any other ideas?

Re: Will MLAG "break" the ring when non-EXOS switches are used?

PeterK — Tue, 12 Nov 2019 15:07:04 GMT

As far as I know, the ISW switches can’t configured as MLAG-Peers.

They only support ERPS (not EAPS) as ring-protocol.

It is possible to do this, but you need to be careful in configuration. ERPS mussn’t be able to block the MLAG-ISC Link.

Re: Will MLAG "break" the ring when non-EXOS switches are used?

kaare_t — Tue, 12 Nov 2019 16:06:21 GMT

Thank you, ISW do not support MLAG at all I believe. I’ve updated a picture below, same topology but I’ve inserted some text. Should I use ERPS ring-protocol “all around” like the picture? Or are there other/better alternatives? Will a full ERPS-ring have any disadvantages?

I’m open for other suggestions/topologies as long as I have redundancy from the central distribution room (I need two stacks). One solution could be to cable each ISW switch separately (using one cable from ISW1 into Stack1 and a cable from ISW1 into Stack2) - see picture below, however we have quite long distances so cabling will be quite expensive. But if this would be a “much greater” solution I will consider this too. I’ve made a picture below, but as mentioned this will trigger a lot of extra cabling for us.