[ILUG] Netopia 2247-02 (fware 7.7.0r6) and IP passthrough

[Maciej Bliziński]

I'm playing with a new home network setup. In asciiart, it looks like this:

Internet
 |
DSL line
 |
Netopia 2247-02 with IP Passthrough option
 |
OpenWRT Kamikaze 7.09 powered router, with public IP,
 |
home LAN

OpenWRT router obtains public IP address from Netopia and does
NATting. All fine, except... all TCP connections are being dropped
every 2 or 3 minutes. This means shutting down all ssh sessions, web
page loading 'gets stuck'. There also are brief losses of sound when
talking over VoIP.

TCP connections need to be dropped when the WAN IP is being changed.
My public IP address indeed changes from time to time, but I also
observe connections dropped without IP address change. If I'm not
mistaken, dhcp renewals shouldn't affect existing TCP connections.

For the time being, I've switched to static NAT, it seems to be
better. But I'd like to avoid having a private address bound to
OpenWRT.

Does anyone here use Netopia 4407-02 IP passthrough function? Is it
broken, or is it fine?

Maciej