Hi,
I was asking myself how are managed dynamic NAT timeout i.e how the duration of an association "private address+private port" <->public address/port is set.
I dont have a great knowledge about netfilter but after browsing Linux code, I have in mind that it has something to do with the conntrack mechanism but I do not understand.
Is it in /usr/src/linux/net/ipv4/netfilter/ip_conntrack_proto_tcp.c for example for TCP? And if it's the cas, how does it work?

I also see the struct nf_conn structure and particularly the timeout field but I dont see where this timeout is set.

Thanks for your answers,
Tanguy.

Not sure how its about the time out of nated connections but if your assumption is right maybe this links can help out

here you find various options for conntrack timeouts
/proc/sys/net/ipv4/netfilter

Mail which talks about conntrack timeouts

or maybe the conntrack command

Anything is better than nothing