[CentOS-virt] Need info on vnet mapping to guests

Sat Oct 24 18:14:22 UTC 2009
Neil Aggarwal <neil at JAMMConsulting.com>

Hello:

I have a host running two KVM guests.  The guests
use br0 and each has a static IP address.

I am trying to figure out if there is a way to
use snmpd on the host to measure the traffic
usage of the guests.  I do not want to require
anything running on the guests since I do not
control them.

Looking at netstat -in on the host, I see this
info:

Kernel Interface table
Iface       MTU Met    RX-OK RX-ERR RX-DRP RX-OVR    TX-OK TX-ERR TX-DRP
TX-OVR Flg
br0        1500   0   237609      0      0      0    13615      0      0 0
BMRU
eth0       1500   0   967594      0      0      0   354576      0      0 0
BMRU
lo        16436   0       63      0      0      0       63      0      0 0
LRU
virbr0     1500   0        0      0      0      0       32      0      0 0
BMRU
vnet0      1500   0    29802      0      0      0   306940      0      0 0
BMRU
vnet1      1500   0   311556      0      0      0   789331      0      0 0
BMRU

Looking at the firewall logs for packets that hit the firewall, 
I see that vnet1 is connected to guestA and vnet0 is connected to 
guestB.

Is there a better way to determine which vnet is connected to
which guest?

Also, does the mapping change when I stop and start guests
or reboot the host?

Thanks,
	Neil

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Neil Aggarwal, (281)846-8957, www.JAMMConsulting.com
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