ssh_exchange_identification: read: Connection reset by peer

I got this while attempting to ssh into a VM on ubuntu. When I pinged the box, I got this:

PING 192.168.1.86 (192.168.1.86) 56(84) bytes of data.
64 bytes from 192.168.1.86: icmp_seq=1 ttl=64 time=0.614 ms
64 bytes from 192.168.1.86: icmp_seq=1 ttl=64 time=1.89 ms (DUP!)
64 bytes from 192.168.1.86: icmp_seq=2 ttl=64 time=0.602 ms
64 bytes from 192.168.1.86: icmp_seq=2 ttl=64 time=0.925 ms (DUP!)

Whoops! The VM was already running and had been granted the exact same IP. It was responding from two places at the same time, which was confusing the hell out of SSH. Just kill one of the boxes and you’re fine (DHCP release/refresh doesn’t work, because both boxes have the same MAC address).

Thanks to this thread for the hint.