If you are in a terminal and want to find the container IDs (CTID) quickly without opening up a browser, run the following:
vzlist
It should return a list of the container IDs, the VM state, their IP addresses and hostnames like so:
CTID NPROC STATUS IP_ADDR HOSTNAME
100 25 running 10.1.1.51 nyx.luna.com
101 17 running 10.1.1.65 euphrosyne.luna.com
102 58 running 10.1.1.22 metis.luna.com
103 15 running 10.1.1.25 curo.luna.com
104 52 running 10.1.1.60 ogmios.luna.com
Quick and easy.