Mc-lag

Hey,Just a quick question on MC-LAGS. If you have CE1 connected to PE1 on ge-0/0/0 and PE2 on ge-0/0/1, why do you need to add the Gig interfaces to an ae? Why not just configure the MC-LAG parameters under ge-0/0/0 of PE1 and ge-0/0/1 of PE2? I understand that the system-id and mc-ae-id need to match from the perspective of the CE, but PE1 could be using ae0 to connect to the CE while PE2 could be using ae3 to connect to the CE. This shows that the ae interface number do not need to be the same on the two PE routers. So if they do not need to be the same, why not just use the physical Gig interface instead of adding it to an ae? Of course this is assuming that you run only one link from PE1 to the CE, and only one link from PE2 to the CE. I understand that an ae link would be necessary if you were running multiple links from PE1 to the CE and multiple links from PE2 to the CE. Just confused why the ae link is necessary when only a single link is used.Thanks!

Find more posts tagged with

SAVE $250 on Your Boot Camp — Use Code "EXAM26"

Exclusively for TechExams members for Infosec Boot Camps starting before April 30, 2026

View Boot Camps

Comments

Aldur

I've never played around with MC LAG, but have you checked out the MC LAG Learning Bytes? Might have the answer to your questions there.

https://www.youtube.com/watch?v=1byapa89L9w

HTH

up2thetime

Aldur wrote: »

I've never played around with MC LAG, but have you checked out the MC LAG Learning Bytes? Might have the answer to your questions there.

https://www.youtube.com/watch?v=1byapa89L9w

HTH

Thanks for the reply. I checked that out, but it didn't explain it. Gonna read through the MC-LAG chapter in the MX-960 book. That might explain it. If I figure it out, I'll let ya know!

tomtom1

The MX book could help you here

Juniper MX Series - O'Reilly Media

up2thetime

Thanks! Excellent resource! I'm going through Chapter 8. It has a lot of really good information! Will post if I come across any other questions.