On 10 December 2015 at 15:00, <m.roth at 5-cent.us> 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? > > > Well there's not much to go on here so you're going to have to provide more detail ... Does the system lose all ipv6 connectivity (is the fe80:: address uncontactable for instance) Does ip addr sh still show the expected global IPv6 address and it's just not responding? Are you using a static ipv6, dhcp ipv6 or SLAAC ipv6 configuration? Does nmcli c sh <conn-name> still have NM thinking there is an address or does that show it as gone as well? Start with those in mind as initial questions for diagnostics...