Date: Tue, 13 Jul 1999 09:03:32 -0400 From: Keith Stevenson <k.stevenson@louisville.edu> To: freebsd-hackers@freebsd.org Subject: Re: Setting up a firewall with dynamic IPs Message-ID: <19990713090332.A8897@homer.louisville.edu> In-Reply-To: <Pine.OSF.4.10.9907132210380.2013-100000@bragg>; from Kris Kennaway on Tue, Jul 13, 1999 at 10:16:32PM %2B0930 References: <199907130856.QAA12434@ariadne.tensor.pgs.com> <Pine.OSF.4.10.9907132210380.2013-100000@bragg>
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On Tue, Jul 13, 1999 at 10:16:32PM +0930, Kris Kennaway wrote: > On Tue, 13 Jul 1999, Stephen Hocking-Senior Programmer PGS Tensor Perth wrote: > > > I was checking out the firewall setup in /etc/rc.firewall, and noticed that > > the simple example relied on a fixed IP address for the external interface. I > > don't know ahead of time what IP address is going to be allocated to me before > > I dial up. Would it be possible to specify an interface (tun0) rather than an > > IP address? > > You could probably do it from /etc/ppp/ppp.linkup, which knows your IP address > as MYADDR. But if you just have asingle machine on the end of the dialup then > I find I can get away with just specifying the netmask from which the dialup > IPs are assigned in place of a single address - all that can happen is that > packets get through your firewall destined to a nonexistent address (i.e. if > you allow incoming port Y traffic then people can send to port Y on > nonexistent IP addresses (i.e. your peer addresses) which will be dropped by > the kernel). Keep in mind that if securelevel > 2, the ipfw rules can not be changed. Regards, --Keith Stevenson-- -- Keith Stevenson System Programmer - Data Center Services - University of Louisville k.stevenson@louisville.edu PGP key fingerprint = 4B 29 A8 95 A8 82 EA A2 29 CE 68 DE FC EE B6 A0 To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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