topic Re: ELRP service VLAN in ExtremeSwitching (EXOS/Switch Engine)

ELRP service VLAN

GCIT_Support — Thu, 20 Jul 2023 20:10:38 GMT

Referencing this article.
https://extremeportal.force.com/ExtrArticleDetail?an=000063093
I would like to create one service VLAN switch solely for ELRP protection. This VLAN would have all switch ports (tagged) excluding the uplink. In my mind this achieves the same result as adding ELRP sessions and port assignments for every physical port without the CPU overhead of multiple ELRP sessions. This seems too simple though. Am i missing something?

Re: ELRP service VLAN

AdrianO — Fri, 21 Jul 2023 12:33:47 GMT

I´ve arrived at the same idea although not implemented yet, don't see any problem with it.

Re: ELRP service VLAN

Bill_Handler — Fri, 21 Jul 2023 12:52:24 GMT

The possible issue could be that if a non-managed/non-VLAN capable switch is connected & looped, the ELRP multicast packet may not traverse that looped switch and the downstream 'dumb' switch could possibly feed that loop back up into the EXOS switch.

We have not tested this, but originally did use the method of a tagged service VLAN for ELRP. We have since moved to using the untagged VLAN (whatever it may be) for ELRP...

Thanks,

Bill

Re: ELRP service VLAN

Brent_Addis — Sun, 06 Aug 2023 08:28:29 GMT

This doesn't help if the loop is on a different vlan though. Perhaps you have vlan2 which is your testing vlan, while vlan 3 has a loop upstream somewhere on a 3rd party switch some random end user has brought in. We test every vlan from all switches, and keep broadcast storm control on all ports.