Re: [Qemu-devel] Two taps, same IP?

[David Barrett <dbarrett@quinthar.com>]

Anthony Liguori wrote:
> David Barrett wrote:
>> I'm considering a tap-based alternative to the -redir patch I proposed 
>> earlier, but I'm just not quite getting how it works.  In particular, 
>> I'm able to access the webserver on one image just fine, but not the 
>> other: wget fails with "Connecting to 172.20.0.3:80... failed: No 
>> route to host."
>>
>> Can you explain why and set me straight?
>>
>> sudo qemu -kernel-kqemu -net nic,vlan=0 -net tap,vlan=0 image0.raw
>> sudo qemu -kernel-kqemu -net nic,vlan=0 -net tap,vlan=0 image1.raw
> 
> You need to pass a unique mac address for each guest.  You're probably 
> getting mac address collisions.

Hm, you're right, they had the same MAC address.  Unfortunately fixing 
that had no effect.  Now I'm launching with:

sudo qemu -kernel-kqemu -net nic,vlan=0,macaddr=00:00:00:00:00:00 -net 
tap,vlan=0 image0.raw

sudo qemu -kernel-kqemu -net nic,vlan=0,macaddr=00:00:00:00:00:11 -net 
tap,vlan=0 image1.raw

I'm still able to wget image0, but so long as it's operational I can't 
wget image1.  Like before, shutting down image0 enables wget access to 
image1.

Looking at ipconfig in the both guests show that the MAC address is 
being picked up correctly, so it must be something else.

Any other ideas?  Thanks!

-david