Subject: Re: IPFilter-related question
To: Zbigniew Baniewski <>
From: Joseph A. Dacuma <>
List: netbsd-users
Date: 05/16/2007 03:42:06
> I'm learning to construct IPFilter-based firewalls, and I've met with
> somewhat strange thing:
> following the example
> I made very similar, simple firewall, just by changing that example
> according to my needs. It was working yesterday, but today in the morning
> I was unable to reach Internet from local network. Something happened(?)
> during the night, although no-one - but me - has access to the machine.
> When
> I restarted the firewall - all went back to normal. But I don't know, for
> how
> long.
> What can be cause of such "automatic blockade"? It seems, that somewhat
> the
> routing (or blocking) rules have been changed? But why?
> It is:
> ipf: IP Filter: v4.1.3 (396)
> Kernel: IP Filter: v4.1.3
> ...on NetBSD 2.0 with kernel 2.0.2.
> --
Hi Baniewski!

Is the connection to your ISP via pppoe and using DHCP? Maybe there lies
your problem. With the exception of my wrong IPF rules, AFAIK, I never had
problems with IPF acting as gateway. However, our set-up here and branch
office are all static since 2.x upto now. You could investigate on that by
turning off your modem for a few seconds and see what gives. Also, check
how long the lease is given to you if your setup is DHCP.

Second, when you say you restarted the firewall, did you mean the entire
machine or flushed and reloaded IPF ruleset? You may have bumped into
common problems like _out of_ or _no more_ in your system.