>> the L3 (IP) based vPC keepalive is purely intended to assist in dealing with >> split-brain if the vPC peer-link is non-functional. >> >> having simultaneous failure of both would be an unusual circumstance, >> particularly if you follow best-practice on the vPC peer-link itself.. > > This is what I had understood as well. Is there any documentation about the > information sent on the keepalive link? Does the frequency remain the same, > regardless of traffic on the box? Even at 400ms intervals, is it still going > to be a very small stream?
all the information contains is details on the vPC domains configured and their status. no data-plane stuff. the frames are quite small, <300 bytes if i recall, frequency is a fixed interval of between 400msec and 1second -- configurable. yes its a small amount of data. see <http://www.cisco.com/en/US/docs/switches/datacenter/sw/4_1/nx-os/interfaces/configuration/guide/if_vPC.html#wp1385808> as i said earlier, the vPC keepalive link is there purely to help ascertain if the vPC 'peer' is still alive in the event that all the vPC peer-link portchannel member links have failed. its purpose is to prevent active-active in a split-brain manner. the keepalive link is not mandatory - but certainly best practice would be for it to be operational as much as possible rather than having it on a network that didn't have the same availability as your primary data path. cheers, lincoln. _______________________________________________ cisco-nsp mailing list [email protected] https://puck.nether.net/mailman/listinfo/cisco-nsp archive at http://puck.nether.net/pipermail/cisco-nsp/
