arp ?

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

Given two NetBSD-9.99.2/amd64 boxen on the same local network, I ssh in from
client to server. On server the server, the arp entry for the client is
"incomplete". If I try then to ssh from the server back to the client, I
have "Host is down". I'm puzzled, as obviously I am typing that command
over the network. No firewalls are involved in this setup.

Thoughts? (All started when ftp of packages from the server kept stalling)

Cheers,

Patrick