For the configuration of multiple IP on ubuntu 14.04, we would make changes to:
/etc/network/interfaces
The server IP is 5.135.141.44
The IP alias is 176.31.176.61
# The loopback network interface
auto lo
iface lo inet loopback
auto eth0
iface eth0 inet static
address 5.135.151.44
netmask 255.255.252.0
gateway 5.135.151.254
iface eth0 inet6 static
address 2001:41d0:0052:0200:0000:0000:0000:0327
netmask 64
post-up /sbin/ip -f inet6 route add 2001:41D0:52:02FF:FFFF:FFFF:FFFF:FF7F dev eth0
post-up /sbin/ip -f inet6 route add default via 2001:41D0:52:02FF:FFFF:FFFF:FFFF:FF7F
pre-down /sbin/ip -f inet6 route del default via 2001:41D0:52:02FF:FFFF:FFFF:FFFF:FF7F
pre-down /sbin/ip -f inet6 route del 2001:41D0:52:02FF:FFFF:FFFF:FFFF:FF7F dev eth0
auto eth0:0
iface eth0:0 inet static
address 176.31.176.61
netmask 255.255.255.255
broadcast 176.31.176.61
gateway 5.135.151.254
post-up /sbin/ifconfig eth0:0 176.31.176.61 netmask 255.255.255.255 broadcast 176.31.176.61
post-down /sbin/ifconfig eth0:0 down
ifconfig
eth0 Link encap:Ethernet HWaddr 00:50:56:01:09:29
inet addr:5.135.151.44 Bcast:5.135.151.255 Mask:255.255.252.0
inet6 addr: 2001:41d0:52:200::327/64 Scope:Global
inet6 addr: fe80::250:56ff:fe01:929/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:10640 errors:0 dropped:14 overruns:0 frame:0
TX packets:541 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:881336 (881.3 KB) TX bytes:61103 (61.1 KB)
eth0:0 Link encap:Ethernet HWaddr 00:50:56:01:09:29
inet addr:176.31.176.61 Bcast:176.31.176.61 Mask:255.255.255.255
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
