The effect of:
echo vs02 > /etc/vservers/anc-test-01/interfaces/0/name

eth0      Link encap:Ethernet  HWaddr 00:0C:F1:B5:61:CF  
          inet addr:192.168.50.17  Bcast:192.168.50.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:2937 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1296 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:318915 (311.4 KiB)  TX bytes:180348 (176.1 KiB)

...
eth0:vs02 Link encap:Ethernet  HWaddr 00:0C:F1:B5:61:CF  
          inet addr:192.168.50.18  Bcast:192.168.50.255  Mask:255.255.255.0
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
...