Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 4 Feb 2001 21:32:49 -0800 (PST)
From:      Rich Wales <richw@webcom.com>
To:        Robert Watson <rwatson@freebsd.org>
Cc:        freebsd-net@freebsd.org, freebsd-stable@freebsd.org
Subject:   Re: BRIDGE breaks ARP?
Message-ID:  <20010205043816.18207.richw@wyattearp.stanford.edu>
In-Reply-To: <Pine.NEB.3.96L.1010204114004.65610J-100000@fledge.watson.org>

next in thread | previous in thread | raw e-mail | index | archive | help
I tried switching the interface on which the IP address was configured.
I'm now giving xl0 (the "external" interface to the DSL modem and the
Internet) the IP address, while rl0 (the "internal" interface linking
the bridge machine to my main home machine) has no IP address.

No difference.  The bridge still doesn't respond to ARP queries for its
own hardware address on the internal (rl0) interface -- but it does
reply to such queries if they arrive on the external (xl0) interface.

I ran "tcpdump -i rl0 arp" and "tcpdump -i xl0 arp" and confirmed the
above.  I saw one interesting thing in the "tcpdump" output:  when my
main home machine was sending ARP queries for the bridge via its "rl0"
interface, the bridge not only failed to reply to these requests, but
(after a while) it started passing them out via its "xl0" interface.

The fact that the bridge is bridging ARP requests for itself strongly
suggests that it's not recognizing the queries as applying to itself
(at least if they arrive via the "rl0" interface).

The question is still open as to why this is happening with the "rl0"
interface, but not the "xl0" interface.  As I said, it doesn't seem to
have anything to do with which of the two bridged interfaces has the
IP address attached to it.

Does this help any?

Rich Wales         richw@webcom.com         http://www.webcom.com/richw/



To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-stable" in the body of the message




Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20010205043816.18207.richw>