Hi all,

First of all I'm using RHEL 6.5

I'm trying to create an ifcfg alias file for eth0 named eth0:0 that is NOT brought up with the Network Manager or on boot. Also, I have a different NETMASK for the alias interface.

The problem I'm having is that no matter what I try, the interface is brought up with the network service, or reboots. Funny thing is, its brought up with the NETMASK of the eth0 interface, not the new NETMASK I specified in ifcfg-eth0:0. I tried setting both ONBOOT=no and ONPARENT=no. If I run 'ifdown eth0:0' and then 'ifup eth0:0' the interface comes back up with the proper NETMASK I specified. I can't really figure out what's going on here. I've been Googling like a mad-man but no luck yet. I can't figure out why its still coming up on boot, and why it comes up with the wrong NETMASK unless I manually bring down the alias interface and back up again.

Contents of ifcfg-eth0:0 :
DEVICE=eth0:0
BOOTPROTO=none
ONBOOT=no
ONPARENT=no
IPADDR=10.11.184.58
NETMASK=255.255.255.248

ifconfig result after boot:

[root@siwr25mxwsrusrciset network-scripts]# ifconfig
eth0 Link encap:Ethernet HWaddr
inet addr:10.10.69.66 Bcast:10.10.69.127 Mask:255.255.255.192
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:57514 errors:0 dropped:0 overruns:0 frame:0
TX packets:43543 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:40171061 (38.3 MiB) TX bytes:13540057 (12.9 MiB)
Interrupt:21

eth0:0 Link encap:Ethernet HWaddr 06:88:41:C4:24:A2
inet addr:10.11.184.58 Bcast:10.11.184.63 Mask:255.255.255.192
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
Interrupt:21

If I run ifdown eth0:0 and ifup eth0:0 the interface starts properly with mask 255.255.255.248. Is there any way to actually stop it from starting automatically, and with the wrong NETMASK?

Thanks!

check and see if you have "network manager" running.
If it's running, shut it down
and kill it at boot with chkconfig.
Now configure your interface and don't forget to sighup inetd when you're finished.
I think that might solve your problem.

It might be in how you are specifying the alias.

In RHEL5, you were supposed to make a second ifcfg file named ifcfg-ethx:y. In RHEL 6.4 or RHEL 6.5, they added the ALIAS stanza for aliases. So you should be able to have a single ifcfg file like this:

~~~
TYPE=Ethernet
NAME=eth0
IPADDR=10.10.69.66
NETMASK=255.255.255.192
IPADDR2=10.11.184.58
NETMASK2=255.255.255.248
~~~

See here: https://access.redhat.com/solutions/8672

That's *with* network manager. If you wish to disable NM, then you use the method you're using with multiple files (a real PITA, IMO), but you must turn off NM, disable NM. THen you can use the ONPARENT options and whatnot.

Thanks to both of your replies.

Unfortunately disabling the NM isn't a permanent solution because my environments are provisioned via a master image template. I am trying to make a case to disable NM on them (for this and a couple other reasons) but that will be a while before it can happen.

GaWdLy your solution worked but I am trying to have the original IP available with the option for the alias to be up or down. Placing them both in the same file doesn't seem to give me this ability.

My solution for now is to script the ip address add command, so I can add and remove on the fly. I do this because my alias IP hops around from VM to VM with my VPN tunnel.

Thanks to both of you for the information, both methods seemed to work for applying the alias.