Problem with Bridging ... and bge devices under FreeBSD 7.x?

Marc G. Fournier freebsd at hub.org
Tue Oct 28 21:38:54 PDT 2008


-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1


I only have one VM running on one server ...

- --On Tuesday, October 28, 2008 21:14:28 -0700 Bakul Shah <bakul at bitblocks.com> 
wrote:

> On Wed, 29 Oct 2008 00:35:35 -0300 "Marc G. Fournier" <freebsd at hub.org>
> wrote:
>> netstat -nr on the 192 server shows the IP to be at:
>>
>> > netstat -nr | grep 168.1.100
>> 192.168.1.100      52:54:00:12:34:56  UHLW        1        1   fxp0   1128
>>
>> which is very odd, as that MAC address is not found via ifconfig -a:
>>
>> > ifconfig -a | grep 52
>> >
>>
>> while arp -a also shows the 52:54 MAC, although MACs for the ifconfig -a are,
>>
>> in fact:
>>
>> > ifconfig -a | grep ether
>>         ether 00:02:b3:ee:da:3e
>>         ether 5e:d1:e6:8b:55:50
>>         ether 00:bd:25:18:6d:00
>
> The setup you get with a tap device talking to qemu is this:
>
>     [host]-tap0----qemu---ed0-[VM]
>
> Each end has its own mac address. The VM's NIC (ed0 or rl0
> or whatever) gets addresses like 52:54:00:12:34:56.  The host
> will have an arp entry for it once the VM sends an arp
> packet.  But tap0 will have an address assigned by the tap
> driver, something like 00:bd:xx:xx:xx.
>
> If you have two VMs running at the same time on two different
> machines and they both have identical MAC addresses, that
> could be part of your problem.
>
> But your network topolgy is still not clear.  What would help
> is something like this:
>
> You have:
> machine A (runs VM A1).
> machine B (runs VM B1).
> machine C (runs windows).
>
> Can you ping from A to C?
> Can you ping from B to C?
> Can you ping from A to A1?
> Can you ping from B to B1?
> Can you ping from A1 to C?
> Can you ping from B1 to C?
> Can you ping from C to A1?
> Can you ping from C to B1?
>
> All of the above should work.  Next you can try tcpdump on
> tap devices to see what is going on.  If you are still
> stumped provide ifconfig -a output on A, B, C, A1 and B1.  On
> windows machine you can do ipconfig/all to get at this
> information (IIRC).



- -- 
Marc G. Fournier        Hub.Org Hosting Solutions S.A. (http://www.hub.org)
Email . scrappy at hub.org                              MSN . scrappy at hub.org
Yahoo . yscrappy               Skype: hub.org        ICQ . 7615664
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.9 (FreeBSD)

iEYEARECAAYFAkkH6M4ACgkQ4QvfyHIvDvPciwCgi3LwM74g8DPrRC4XlkNQgFD4
eRgAnj6/CUVTkrzwr8GnzawWKlbfCWBc
=KgEt
-----END PGP SIGNATURE-----



More information about the freebsd-stable mailing list