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I'm setting up a CentOS server and I have no intention to use IPv6 on it by now. Because of this, I have a few simple questions:

  • Is there any problem in blocking all IPv6 traffic on this machine (in and out)?
  • If not, how can I accomplish it?


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You can, but you shouldn't. Dupe of… anyway. – womble Jul 27 '11 at 23:10
Correct me if I'm wrong, but if you don't have an IPv6 upstream IPv6 traffic is not going to be going out your connection regardless. – Jeremy Bouse Aug 22 '11 at 2:31
Without additional work you probably don't have a global IPv6 routable address so the issue is moot. – Steve-o Aug 25 '11 at 3:30

I don't think I'd block it; I think I would just disable the ipv6 stack.

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you can either disable it in the config scripts or use sysctl net.ipv6.conf.all.disable_ipv6=1 to totally turn it off in the kernel.

Nonetheless... if you won't actually have IPv6 connectivity, I would argue it's not worth the effort.

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