geert.hendrickx@ua.ac.be said:
> add static ARP entries, listed in /etc/arp.conf

I'd prefer a slightly more expensive solution:
Have only the IP addresses in /etc/arp.conf and look
up the IP-ether pairs in /etc/ethers. This avoids
duplication of information, and it would allow to
have the /etc/ethers database distributed network-
wide, eg. per LDAP. (security considerations aside,
but there are means to authenticate)
Something like
while read ip; do
	arp -s $ip `getent ethers $ip`
done

Just needs "getent" to handle "ethers".

best regards
Matthias