How to identify DomU's ip without login to it

How to identify DomU's ip without login to it

1. Find domU's mac:

localhost:~# xm network-list 5 | grep -v MAC | awk '{print $3}'

00:16:3e:03:47:36

2. Find domU's bridge

localhost:~# brctl show 

bridge name bridge id STP enabled interfaces

eth0 8000.1c6f650addfe no vif5.0

peth0

virbr0 8000.000000000000 yes

So the bridge of domU (id: 5) is eth0

3. Use tcpdump to identify domU's ip

localhost:~# tcpdump -n -i eth0 ether src 00:16:3e:03:47:36

tcpdump: verbose output suppressed, use -v or -vv for full protocol decode

listening on eth0, link-type EN10MB (Ethernet), capture size 96 bytes

16:47:11.320253 IP 192.168.25.22.filenet-rpc > 192.168.100.10.domain:  39150+ A? www.baidu.com. (31)

16:47:11.320995 IP 192.168.25.22 > 119.75.218.77: ICMP echo request, id 35854, seq 1, length 64

16:47:11.349207 IP 192.168.25.22.filenet-rpc > 192.168.100.10.domain:  15635+ PTR? 77.218.75.119.in-addr.arpa. (44)

So the ip of domU (id: 5) is 192.168.25.22

Note: This method requires that the vm must be sending some packets to internet.