IPv6 global address removed from the interface

[a_aronsky]

Dear all,

I'm working with the following CentOS version:
2.6.32-431.23.3.el6.i686 #1 SMP Thu Jul 31 14:37:53 UTC 2014 i686 i686 i386 GNU/Linux

I've noticed that when I add some global IPv6 address to the interface, and then down/up the interface via 'ip' command, the IPv6 address I previously added does not come back. So I have to add it manually again (after which it all resumes working fine). This is of course very inconvenient. Does anyone encounter such stuff? Any suggestion?

Kind regards,
A.

[TrevorH]

You are running an extremely backlevel version of the kernel (more than a year old), please run yum update to bring yourself up to date. That's 6.6 at this monent but 6.7 is imminent.

If you want persistent addresses assigned to an interface then you should add the necessary parameters to your ifcfg file for the interface and use ifdown/ifup to bring the interface up and down.

[a_aronsky]

TrevorH,

Thank you for prompt reply! I know we are sort of outdated I will run yum update as you suggest and see whether it helps.
Re. ifcfg files, we do not want the addresses to be persistent over reboots - only as long as our application is running.

Best regards,
A.

[a_aronsky]

Trevor,

FYI, I upgraded to 6.6, but the problem is still there. Just scratching my head why it works this way...

[root@Infra-L-AlexA-65 ~]# cat /etc/redhat-release
CentOS release 6.6 (Final)

Regards,
A.

[TrevorH]

Because that's the way it works. You took the interface down so it forgets its configuration. The problem is that you want some sort of non-persistent persistent configuration and it just doesn't work that way.

[a_aronsky]

OK, I understand.
But why then the IPv4 addresses remain? Seems to me rather inconsistent.
Regards,
A.

[aks]

Persistence is configured in /etc/sysconfig/networking-scripts/ifcfg-eth0 - assuming you don't use NetworkManager.

[gerald_clark]

You might also be using dhcp for IPV4.