MLAG - best practices to avoid as much as possible data traffic between ISC link

[Luis_Oliveira]

Dear All,

Can you please give me some hints about the best configurations on MLAG peers and on connecting switches/servers about LACP in order to avoid, as much as possible, data traffic on ISC links?
I now how to do it on EOS VSB setting the local preference, but can't find the same feature on MLAG.
Many thanks

[Paul_Russo]

Hey Luis

Just to clarify you are asking which algorithm should you use on the server or the 3rd party switch to distribute their traffic to the MLAG peers? That depends on the device as the algorithm is a hop by hop count. So the decision which link to take is up to the originating device. For example if you use address based traffic from the same originating device to the end device will go the same link.

As for the ISC link the switch will forward traffic based on the MAC address in its tables. So in the design you have above the server determines which link to send it to based on its Algorithm. it sends it to either MLAG sw1 or sw2. That switch knows that the destination MAC lives off of its port 1 (for example) and will send it directly. It will not send it over the ISC because the MAC table doesn't have that MAC on the ISC port. The only traffic that goes across the ISC are broadcast and multicast packets. When that happens it is up to the MLAG Peer Port ( the port directly connected to the end device) to drop the packet.

I hope that helps. if not please let me know where I went off topic.
Thanks
P

[Luis_Oliveira]

Hi Paul,
Many thanks.

The question is: which spreading algorithm should i use on the LAGs configuration in order to avoid as much as possible traffic on the ISC links.
I assume 802.3ad protocol on 3rd party.
The customer uses Hypervisor as virtualisation platform. On the server side i don't have a clue about how to configure teaming ou lacp support.
Cheers,

Luís Oliveira