Re: [Xen-users] question on bridged OR routed configuration & public IP addresses

[xenlist@xxxxxxxxxxxxx]

Steven Timm wrote:
> Use the bridging (not the nat).  The machines will have public/routable.
> We are doing this now.
I'm still having trouble with this.  I started with a clean install of 
CentOS 5.1.  I am testing it on an internal network currently until I 
get the problems worked out.
Here's what I have:

1) I have set the dom0 server to have an IP address of 192.168.1.200/24 
on eth0.  This machine sees the actual network default gateway of 
192.168.1.1.
2) CentOS installs the following default.xml file under 
/etc/libvirt/qemu/networks:
<network>
  <name>default</name>
  <uuid>cut-out</name>
  <bridge name="virbr0" />
  <forward/>
  <ip address="192.168.122.1" netmask="255.255.255.0">
    <dhcp>
      <range start="192.168.122.2" end="192.168.122.254" />
    </dhcp>
  </ip>
</network>

3) I changed the above file to use the IP address 192.168.1.199 with the 
same netmask.  I am, after all, wanting to verify that I can have dom0 
and domU on the same network as the gateway and other systems.
4) I created a logical volume for my domU.

5) I created a config file for my hardware virtual machine which looks 
like this:
****************
imprt os, re
arch = os.uname ()[4]
if re.search('64', arch):
        arch_libdir = 'lib64'
else:
        arch_libdir = 'lib'
kernel = "/usr/lib/xen/boot/hvmloader"
builder='hvm'
memory = 1024
shadow_memory = 8
name = "servername"
pae=1
vif = [ 'type=ioemu, bridge=virbr0, ip=192.168.1.201' ]
disk = ['phy:/dev/VolGroup00/lvguest,hda,w', 'phy:/dev/hdb,hdc:cdrom,r']
device_model = '/usr/' + arch_libdir + '/xen/bin/qemu-dm'
boot='dc'
sdl=0
vnc=1
vnclisten='0.0.0.0'
vncunused=1
stdvga=0
serial='pty'
*****************

6) I installed a copy of CentOS on this HVM.

7) I configured the network on this domU to use 192.168.1.201 with a /24 
netmask.
8) I turned OFF iptables on both machines to ensure there are not 
blockages there.
SO, at this point, from the domU, I can:

        ping 192.168.1.201 (theh domU itself)
        ping 192.168.1.199 (the virbr0 IP address)
        ping 192.168.1.200 (the dom0)

BUT, I cannot ping beyond the dom0.

ALSO, from dom0, I cannot ping 192.168.1.1, the default gateway, even 
though I could before hand.
If I do a netstat -rn, it appears that I have TWO network routes:

Destination     Gateway         Genmask         Iface
192.168.1.0     0.0.0.0         255.255.255.0   virbr0
192.168.1.0     0.0.0.0         255.255.255.0   eth0
169.254.0.0     0.0.0.0         255.255.0.0     eth0
0.0.0.0         192.168.1.1     0.0.0.0         virbr0

So the default route is pointing to the bridge.  I'm not sure if that is 
correct or incorrect behavior, as I have not gotten this to work yet.
I'm also guessing that at least ONE of these 192.168.1.0 network routes 
is unnecessary, but I'm not sure which.
I'm also unclear as to how to fix it and what configuration files need 
to be changed in order to maintain proper behavior across reboots.
Any ideas or pointers would be appreciated.  Working examples get bonus 
points.  8^)
Thanks.

LT


--
Craig Thompson, President
Caldwell Global Communications, Inc.
423.559.5465 (v)
423.559.5145 (f)
"Why Surf When You Can Fly?" (TM)

Visit http://www.thompsonreviews.com for family friendly reviews

_______________________________________________
Xen-users mailing list
Xen-users@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-users