**Subject:** Re: NAT timeouts

**To:** andrej misovic *<ado@nirvanaclub.sk>*

**From:** David Maxwell *<david@vex.net>*

**List:** netbsd-users

**Date:** 07/07/2004 10:33:21
On Tue, 06 Jul 2004, andrej misovic wrote:
> hello,
> how long are NAT connections cached?
>
> I use jabber client (psi) behind netbsd box (gw/fw/nat)
> which send keep-alive packets,
> but connection to jabber server die after 8-15 sec.
> I'm afraid, that reason is short NAT conection cache..
> or am I wrong?
10 minutes. If your NAT tables are too small however, entries can die
sooner (though I've not seen 8-15s...)
Check:
src/sys/netinet/ip_nat.h
#define DEF_NAT_AGE 1200 /* 10 minutes (600 seconds) */
#undef LARGE_NAT /* define this if you're setting up a system to NAT
* LARGE numbers of networks/hosts - i.e. in the
* hundreds or thousands. In such a case, you should
* also change the RDR_SIZE and NAT_SIZE below to more
* appropriate sizes. The figures below were used for
* a setup with 1000-2000 networks to NAT.
*/
#ifndef NAT_SIZE
# define NAT_SIZE 127
#endif
#ifndef RDR_SIZE
# define RDR_SIZE 127
#endif
#ifndef HOSTMAP_SIZE
# define HOSTMAP_SIZE 127
#endif
#ifndef NAT_TABLE_SZ
# define NAT_TABLE_SZ 127
#endif
#ifdef LARGE_NAT
#undef NAT_SIZE
#undef RDR_SIZE
#undef NAT_TABLE_SZ
#undef HOSTMAP_SIZE 127
#define NAT_SIZE 2047
#define RDR_SIZE 2047
#define NAT_TABLE_SZ 16383
#define HOSTMAP_SIZE 8191
#endif
--
David Maxwell, david@vex.net|david@maxwell.net --> Unless you have a solution
when you tell them things like that, most people collapse into a gibbering,
unthinking mass. This is the same reason why you probably don't tell your
boss about everything you read on BugTraq! - Signal 11