eth0      Link encap:Ethernet  HWaddr 00:13:20:11:2B:C7
          inet addr:xxx.bbb.c.a11  Bcast:xxx.bbb.c.255  Mask:255.255.255.0
          inet6 addr: fe80::213:20ff:fe11:2bc7/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:964 errors:0 dropped:0 overruns:0 frame:0
          TX packets:437 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:86778 (84.7 KB)  TX bytes:50930 (49.7 KB)
          Interrupt:17

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:305 errors:0 dropped:0 overruns:0 frame:0
          TX packets:305 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:29657 (28.9 KB)  TX bytes:29657 (28.9 KB)

and finally this is in the interfaces
auto lo
iface lo inet loopback

auto eth0:0
iface eth0:0 inet static
#name Ethernet alias LAN card
address xxx.bbb.c.a12
netmask 255.255.255.0
broadcast xxx.bbb.c.a55
network xxx.bbb.c.0

auto eth0:1
iface eth0:1 inet static
#name Ethernet alias2 LAN card
address xxx.bbb.c.a13
netmask 255.255.255.0
broadcast xxx.bbb.c.255
network xxx.bbb.c.0