N9K vPC peer link

[mmc11]

Hi,

Is it recommended to use even number of links for an N9k vPC peer link? like if I use 3 links, would it matter?

[mmc11]

Hi @Sergiu.Daniluk , any idea?

[Sergiu.Daniluk]

It is not a problem if you want to use more than 2 links in the peer-link. Actually, if you have a modular switch (N9500) it would be recommended to increase the number of links across multiple linecards. 
In regards to load-balancing, not sure what @Pavel Tarakanov refers to - maybe he can detail more about it, but on Nexus switches the default balancing on L2 PO happens based on src/dst MAC. 

Stay safe,

Sergiu

[mmc11]

Thank you @Sergiu.Daniluk, however, does an odd number of links in peer-link cause an issue, for example: 3; or it is irrelevant? 

[Sergiu.Daniluk · Accepted solution]

Irrelevant on Nexus switches. On other platforms (e.g. Catalyst 6500) there are different hashing algorithms and could impact the load balancing. 

[Pavel Tarakanov]

It will work, but balancing will be not optimal, like 2-1-1.

In general two physical ports need for redundancy (if one of the link fail), more - should be considered if high amount of traffic expected.

https://www.cisco.com/c/en/us/support/docs/lan-switching/etherchannel/12023-4.html