Masquerade and dhcp lease renewal - what happens?

[Henrik Nordstrom]

On Mon, 3 Oct 2005, Henning Riis Rasmussen wrote:

> My ISP (Telia, Sweden) uses a DHCP lease time of 10 minutes leading to
> constant renewal of the lease.
>
> If I use "-j masquerade" instead of "-j snat" I cannot have any
> longlived connections (they all die with "new not syn" or "invalid").

Seems your DHCP server is resetting interface (down/up) on each renewal 
then.

Does "tcpdump -i eth0" surive a renewal? If not you should defeintely look 
into using another DHCP client.

> What is supposed to happen to the masquerade nat entries when a dhcp
> renewal happens, particularly one that doesn't actually change the IP
> address to a new one?

In 2.6.13 the connections is cleared from conntrack if the IP address is 
deleted or if the interface is brought down.

Regards
Henrik