Date: Mon, 7 Feb 2005 10:50:21 GMT From: "Emil Cazamir" <emil.cazamir@galati.rdsnet.ro> To: freebsd-bugs@FreeBSD.org Subject: RE: kern/76966: udp/520 reply packets when routed is not running Message-ID: <200502071050.j17AoLNM057775@freefall.freebsd.org>
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The following reply was made to PR kern/76966; it has been noted by GNATS. From: "Emil Cazamir" <emil.cazamir@galati.rdsnet.ro> To: <dwmalone@maths.tcd.ie> Cc: <FreeBSD-gnats-submit@FreeBSD.org> Subject: RE: kern/76966: udp/520 reply packets when routed is not running Date: Mon, 7 Feb 2005 12:53:08 +0200 -----Original Message----- From: dwmalone@maths.tcd.ie [mailto:dwmalone@maths.tcd.ie] Sent: 6 februarie 2005 19:41 To: Emil Cazamir Cc: FreeBSD-gnats-submit@FreeBSD.org Subject: Re: kern/76966: udp/520 reply packets when routed is not running On Tue, Feb 01, 2005 at 05:35:28PM +0200, Emil Cazamir wrote: > >Description: > The FreeBSD kernel seems to respond to udp/520 packets even when > there is no such daemon running. There's no code in the FreeBSD kernel for doing this, however I think I know what is going on... > 17:03:32.185977 0:f:3d:47:8b:de ff:ff:ff:ff:ff:ff 0800 60: 192.168.0.10.520 > > 192.168.0.255.520: RIPv1-resp [items 0]: (DF) > 17:03:32.186153 0:0:0:0:0:2 0:0:0:0:0:1 0800 60: 192.168.1.33.520 > > 192.168.0.255.520: RIPv1-resp [items 0]: (DF) Your FreeBSD maching gets a packet for 192.168.0.255 - I suspect you have the netmask on your FreeBSD machine set incorrectly so it does not consider this a broadcast address. Consequently, it probably considers this a misdirected packet and so sends an ICMP redirect and then forwards the packet, in this case to the default router. I'm not sure why the source address on the packet has changed - that bit seems a bit odd. David. There is no problem with the netmask, there are several subnets sharing the same wire. I lokked into few kernel config files and I didn't found anything specific. I think that the cause of what's happening is somewhere in natd/libalias, all the machines which respond to [or forward] udp/520 packets are running natd. I will make available kernel config files, process listings, etc if it is required.
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