On Thu, 10 Dec 2015 16:00, m.roth@... wrote:
We've started having a problem with a CentOS 7 server. It looses its IPv6 address, if I understand this issue correctly. We can get in, if we do ssh -4, though.
In the logs, I'm seeing this about twice an hour: <warn> (pid 98466) unhandled DHCP event for interface ens3f0
Now, in googling, I get very few hits putting quotes around "unhanded dhcp exception" - in fact, the only one I found that seemed to talk about it was from someone's slackware box, where there was some sort of configuration, perhaps similar to ifcfg-<if>, and they were telling that person to remove it, because it conflicted with what Networkmanager was trying to do, leaving it in a confused state.
Any thoughts?
mark
My first thought upon reading this was: Well, let's block / drop the irritating packets via firewall / iptables.
Is the source of these packets allowed to contact your box at all? - No : then block it fully, ipv4 and ipv6 - Yes: block all dhcpv4 / dhcpv6 / radv traffic to and from this source. or even more aggressive: first block this box, second only open the minimum required ports to that box.
IMHO, Networkmanager(and its underlaying helpers) should be much more carefull in handling Router / DHCP stuff. It's biggest niggle for me is a missing white- and black-list for (dis-)allowed routers / dhcp-servers.
Is this the "Right(tm)" thing to do? Dunno, but that would be my gut-telling.
- Yamaban