RTNETLINK answers: File exists

[suityou01]

This is really puzzling. I build a Centos 7 server.

I'm in the process of installing zarafa. I got to the point of starting up the services and when I try and start the zarafa gateway service it fails.

Failed to start LSB: Zarafa Collaboration Platform's POP3/IMAP Gateway.

OK so I try and start the network service and I get :

Aug 13 16:35:07 myservername network[24431]: RTNETLINK answers: File exists
Aug 13 16:35:07 myservername network[24431]: RTNETLINK answers: File exists
Aug 13 16:35:07 myservername network[24431]: RTNETLINK answers: File exists
Aug 13 16:35:07 myservername network[24431]: RTNETLINK answers: File exists
Aug 13 16:35:07 myservername network[24431]: RTNETLINK answers: File exists
Aug 13 16:35:07 myservername network[24431]: RTNETLINK answers: File exists
Aug 13 16:35:07 myservername network[24431]: RTNETLINK answers: File exists
Aug 13 16:35:07 myservername systemd[1]: network.service: control process exited, code=exited status=1
Aug 13 16:35:07 myservername systemd[1]: Failed to start LSB: Bring up/down networking.
-- Subject: Unit network.service has failed

Bearing in mind this is a fresh install, and the network service hasn't worked since I built the machine on Monday.

This server has 2 ethernet ports so the configured interfaces are

em1
em2
lo

I have been googling all afternoon but really don't know what this error message means. Can anyone suggest how to go about trouble shooting?

"File exists" is just a bit too vague.

[TrevorH]

In my experience, "file exists" in network terms means "you have a duplicate route". Do you have route-$interface files? Or routes supplied by a DHCP server?