eaps and mlag

[Fed_Ex]

Hello extreme guys

is it possible to configure a MLAG ISC-Link over protected eaps? Or are there any technical issues?

Thanks a lot for your reply.

[Paul_Russo]

The VLAN is the thing that counts. Broadcast comes across the VLAN and will go out any port in that VLAN. So if a broadcast comes across the ring and goes into slot 3, for example, and the ISC is on slot 2 and also has that VLAN the broadcast will go across the ISC and will loop back.

This is out of the concepts guide

However, flood and multicast traffic will traverse the ISC but will be dropped from MLAG peer port transmission by the ISC blocking filter mechanism. The ISC blocking filter matches all Layer 2 traffic received on the ISC and blocks transmission to all MLAG ports that have MLAG peer ports in the active state.

SInce the EAPS ports are not MLAG peer ports the traffic will not be blocked

Does that help?

P

[Conor]

Thanks Paul
This should work ! The master in the ring is the last edge switch before the 2nd BD

[Conor]

Thanks for Comment;
I am using one or the other MLAG or EAPS.
The only crossover is that the the same VLAN is switched on both my EAPS ring and my Stack (via MLAG)

[Paul_Russo]

Good Morning Conor

The thing to remember with MLAG is that traffic received on MLAG peer ports are not sent our other MLAG Peer ports however if traffic comes into the switch from other ports that traffic is sent on. The filtering of broadcast and multicast is done on the MLAG peer ports not on the ISC.

In your case traffic on a VLAN is coming in EAPS ports that are not MLAG peer ports so that traffic is then sent across the ISC and since the other switches EAPS ports are not MLAG peer ports they are sent out causing the loop.

If you are doing EAPS and MLAG ISC use the same ports as long as those ports will not be blocked by EAPS.

Hope that helps
P

[Ron_Huygens]

Did you have the same route through MLAG and EAPS? Both are L2 protocols and that can cause the loop. An edge switch should only connected through either EAPS or MLAG on the same links.