[CentOS-virt] Xen networking - pulling out my hair

Mon Apr 28 20:25:38 UTC 2008
Kai Schaetzl <maillists at conactive.com>

Ken Bass wrote on Mon, 28 Apr 2008 15:08:22 -0400:

> In anaconda, I select manual/static IP address. I enter 192.168.139.4
> with subnet mask of 255.255.255.255, gateway/ns of 192.168.144.5

AFAIK, there is no route from 192.168.139.4 to 192.168.144.5. You need to 
specify a gateway in that net!
Your earlier explanation looks a bit like you think your packets somehow 
"go thru" your Dom0 and rely on the network settings on it. That's not the 
case. Once the initial bridge is setup you can use *any* IP number on the 
DomU that you like, there is no connection to the IP numbers that are 
configured for the Dom0.
In other words, if you have a router with 192.168.1.1 and 192.168.2.1 and 
a Dom0 with 192.168.1.2 and a DomU with 192.168.2.2 you can reach that 
router from both with the standard (older) xen bridging that comes with 
CentOS 5. No problem. Also, you do not need any Iptables rules.
I think you needed nothing to change in your networking setup. I have been 
using static IP addresses with CentOS 5/5.1 before upgrading to Xen 3.2 
and they worked just fine. The only problems I had (and still have) were 
with DHCP.

Kai

-- 
Kai Schätzl, Berlin, Germany
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