Hello, I have to add a second IP address to one server running CentOS 6.4. I used the method of copying ifcfg-eth0 to ifcfg-eth0:1 and modify the necessary data.
The original file looks like this:

[root@nncsrv2 network-scripts]# vim ifcfg-eth0
DEVICE=eth0
TYPE=Ethernet
UUID=f2954b4d-0714-4678-ada6-424066e9ab26
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=none
IPADDR=172.18.4.44
PREFIX=24
GATEWAY=172.18.4.1
DNS1=10.70.44.30
DNS2=10.73.33.62
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0"
HWADDR=D8:9D:67:2AB:10
LAST_CONNECT=1389637604
~

and I modified ifcfg-eth0:1 file to this:

[root@nncsrv2 network-scripts]# vim ifcfg-eth0:1
DEVICE=eth0:1
TYPE=Ethernet
UUID=f2954b4d-0714-4678-ada6-424066e9ab26
ONBOOT=yes
NM_CONTROLLED=yes
BOOTPROTO=none
IPADDR=172.18.4.45
PREFIX=24
GATEWAY=172.18.4.1
DNS1=10.70.44.30
DNS2=10.73.33.62
DEFROUTE=yes
IPV4_FAILURE_FATAL=yes
IPV6INIT=no
NAME="System eth0:1"
HWADDR=D8:9D:67:2AB:10
LAST_CONNECT=1389637604
~

After restartitg the networking service, the problem is that the IP dynamically assigned to the interface is just the new one (172.18.4.45). From other server I can ping 172.18.4.45 but not the original 172.18.4.44. I need both IP running.
Any help, please?
Thanks.

Hello and welcome to LQ.

Might go over this and see if some small mistake happened. ??

http://www.tecmint.com/create-multip...ork-interface/


Generally you'd go here. https://www.centos.org/docs/5/html/D...nterfaces.html

Multiple cards may cause some issues with examples.

also be aware
CentOS 6.4 is missing about the last YEARS of security updates
cent dose NOT backport security fixes to older versions like RedHat dose

6.4 went End of life with the release of 6.5 in Dec.2013

Finally, I solved it by adding:

IPADDR2=172.21.8.11
PREFIX2=24

to the original ifcfg-eth0 file.
But I also had to disable the NetworkManager for this to work fine.
The reason is explained here: http://www.behindtherack.com/sub-int...hat-6centos-6/

Thanks.

Thanks for the update and solution.