I have not used BSD in a while, so I may be speaking out of turn here, but have you tried clearing the arp cache forcing it to create a new entry to look up?

From: plug-discuss-bounces@lists.plug.phoenix.az.us [mailto:plug-discuss-bounces@lists.plug.phoenix.az.us] On Behalf Of Eric Cope
Sent: Thursday, April 02, 2009 1:51 PM
To: Main PLUG discussion list
Subject: Re: FreeBSD OpenVPN and SMB Connection Issues

Anyone have any ideas?

On Wed, Apr 1, 2009 at 9:56 PM, Eric Cope <eric.cope@gmail.com> wrote:

Hello all,
I am running a FreeBSD 7 server at home. I recently filled up the /usr partition. I cleaned it out, but now I can't connect with my OpenVPN client nor via Samba. I can connect via SSH. The logs look normal, other than these lines in debug.log

...
Mar 26 23:50:58 e-server kernel: arplookup 216.9.190.124 failed: host is not on local network
Apr 1 21:48:09 e-server kernel: arplookup 216.9.190.124 failed: host is not on local network

followed by "this message repeated xxx times" several times.

Any ideas?

Eric