On Dec 11, 2014, at 3:10 AM, Alexander Dalloz <ad+lists at uni-x.org> wrote: > Am 11.12.2014 um 04:48 schrieb Warren Young: >> >> the stock configuration of Apache only listens for IPv6 connections: > > No, that's just the way it is displayed for apache. In fact the service listens on IPv4 as well (given we speak about the default configuration with `Listen 80'). > > Easy to verify. We noticed this problem when web browsers would refuse to connect to the server. *Then* we discovered the netstat oddity, and *then* we found that changing the Listen line in httpd.conf fixed it. That leaves me still wanting an explanation for what happened. New guess: there’s a difference between the IPv4 and v6 firewalls, so that changing the Listen line caused Apache to avoid the problem on the v6 side. I guess we’ll just keep an eye out when we build our next EL7 box...