You do not consider IPv6 an option?
ipv6 is working just fine even here at IETF49 venue, it's so much more
convenient than IPv4, for couple of reasons.
- DHCPv4 lease time is set to 10 minutes, and we keep changing IPv4
address. if I suspend my laptop, go to bathroom and resume, i'll
have to reconnect all of IPv4 TCP sessions I had.
we do not have the problem with IPv6.
- we have no problem reaching IPv4 world with IPv6, we have IPv6-to-
IPv4 translator here (http://www.kame.net/ietf49/).
so, migrate to IPv6. you will be happier.