[c-nsp] Some basic vPC questions (nexus 3000)

[Drew Weaver]

Greetings,

We are purchasing two Nexus 3000 switches to aggregate some 48 port 1G switches and plan on using vPC for redundancy.

http://www.cisco.com/en/US/prod/collateral/switches/ps9441/ps11541/white_paper_c11-685753.html

When I was reading the vPC whitepaper (referenced above) for the Nexus 3000 it mentions two different types of vPC link:

#1 The vPC peer keepalive link (whitepaper suggests that this traffic can run over the mgmt. interface)
#2 The vPC peer link (needs to be at least two 10G ports in a port channel)

My questions are 
       
       What happens to the traffic if the vPC peer keep alive communication fails between the two vPC members?
       Depending on the answer to the question above, is it possible to make the vPC peer keepalive link redundant?
       
      Can you add more members to the vPC peer link port channel without disrupting traffic flow?
       
       Has anyone run into any unexpected caveats or amusing issues with vPC that they would like to share?
       
Thanks and happy Friday!
-Drew