ARP table entries / ifconfig needs to be issued twice when moving IP

[Michael Gmelin]

> Reminds me of what I encountered recently with two virtual
> machines at my provider. I haven't further dug into this, as
> I didn't check `arp -an`, but what I saw was switching an IP
> address from hosts A to B resulted in pings from host C to arrive
> at A. Host C said they got lost while tcpdump showed incoming
> packets at A although they should have gone to B.

As the packets came from host C, this is expected behaviour. Host C had
the ARP entry cached (or if it wasn't on the same network, some network
equipment had).

What I'm describing is the machine having the IP address configured
not creating a permanent entry in the local ARP table for its own
interface.

- Michael

-- 
Michael Gmelin