Date: Tue, 25 Jan 2011 16:32:26 +0300 From: Alexander Zagrebin <alex@zagrebin.ru> To: freebsd-net@freebsd.org Subject: 8.2-PRERELEASE: if_bridge ARP and broadcasts issues Message-ID: <20110125133226.GD67220@gw.zagrebin.ru>
next in thread | raw e-mail | index | archive | help
--MW5yreqqjyrRcusr
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Hi!
I've found some issues with the if_bridge on 8.2-PRERELEASE.
1. An ARP issue
Suppose we have a box with the 4 interfaces: nic0, nic1, nic2, nic3.
The interfaces are linked pairwise using 2 bridge(4) interfaces: bridge0
and bridge1. Only nic0 has an IP address assigned (for example,
192.168.0.1/24).
So we have configuration like this:
192.168.0.1
---nic0---+ +---nic2---
| |
bridge0 bridge1
| |
---nic1---+ +---nic3---
The problem: when ARP query about MAC address of 192.168.0.1 is received
on the nic2 or nic3, then system responds with the MAC address of the nic0,
though networks on the bridge0 and bridge1 are completely independent.
IMHO, it isn't correct.
The reason is in ARP handling code: it looks for an address of the interface
belonging to a bridge, but there is not check that a bridge is the same.
Attached patch (patch-if_ether.c) fixes the issue.
2. Broadcasts issue
I have a box with two NICs: re0 and wlan0. re0 and wlan0 are members of the
bridge0. re0 has IP address 192.168.1.1; wlan0 hasn't an address configured.
I have the samba installed. The smbd and nmbd listens on the 192.168.1.1.
There are no problems with the clients connected to the re0, but the samba
clients connected to the wlan0 has problems with the network browsing and
domain logons.
I've found that nmbd doesn't receive udp broadcasts received on the wlan0,
though bridge0 successfully retransmits this broadcast out of re0.
I've looked in the sources, and it seems that in this case subnet broadcasts
have to be handled in ether_output(), but this doesn't work anyway...
Can anybody help to fix this issue?
--
Alexander Zagrebin
--MW5yreqqjyrRcusr--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20110125133226.GD67220>