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MLAG vs Stack what am i missing

MLAG vs Stack what am i missing

Chris_Chance
New Contributor
Can't seem to wrap my head around the reason for using MLAG vs Stacking, I'm planning to use 2 x670's as a 10gigabit aggregation hub for our remote sites, but i want redundancy, so the idea was run 1 fiber to each of the x670's and run mlag so if 1 x670 fails, tada still up and working... But then i got to thinking if i stack those 2 x670's and use a standard lag group from 1:1 and 2:1 to the remote site, isn't it IDENTICAL, but i get the benefit of not dealing with the mlag, not having to deal with managing 2 core switches, and still keep the same load balancing, same redundancy, same resilience and high availability? I feel like theirs got to be something here I'm missing
23 REPLIES 23

Rui_Marques
New Contributor
There's a very importante feature here that has been disregarded by everyone so far. Stacking only gives you the master control plane, and the other switches provide additional ports. Processing is made only by the master. On MLAG, processing is done by BOTH members. MLAG ports count only as 1 switch, since they are beeing used evenly on both.

dflouret
Contributor
eyeV,

This is a WILD guess.

When traffic is sent from S switches to the router, it gets evenly balanced (sort of...) among the LAG members going to the X switches.

But when traffic is sent from the router to the S switches it gets to X1 and this switch will send traffic to the S switches using its local LAG links and not through X2 links, which would require traversing the ISC. Thus, you'll see a lot more traffic on the links connecting to X1.

I don't know if this is exactly what is happenning, but as my italian grandmother used to say...

se non è vero, è ben trovato (If it is not true, it is a good story). Hahahaha

eyeV
New Contributor III
Hi guys! It was my mistake. Sorry )

eyeV
New Contributor III
Bottom switches have one line about LAG in their configs.
enable sharing 25 grouping 25-26 algorithm address-based L2

I can't change hash, because it's temporary situation. We are going to "normalize" it tommorow.
GTM-P2G8KFN