[CentOS] Centos 7 Network Question

Mon May 11 03:57:01 UTC 2015
david <david at daku.org>

I have a question about the network and Centos 7

I am experimenting with two C7 installations:
- On relatively new hardware, configured with fixed IP address in IPV4 only
- on top of Windows, using VMWare, sharing my windows connection via 
Vmware's bridge with IPV4 only.

On both configurations, I run a script every five minutes to test the 
network.  The sequence is as follows:
- Find the default interface using "ip route"
- Find that interface's IP address by scanning the output of "ip 
route" for a match in interface.

If the above tests fail to resolve, I issue "systemctl restart 
network", and post a mail message to myself.  When this happens, the 
network does indeed come back correctly.

I do the same sequence on Centos 6 installations, (using "system 
network restart").

I find that on Centos 6, I almost never get notified that the restart 
occurred (except when there's a real reason).

On Centos 7, however, I find that about once a day or so, I get 
notified, even though there's nothing that has changed.

On Centos 6, I left the avahi daemon running.  On Centos 7, I 
disabled avahi (because with it enabled, I was getting this failure 
once every few hours).

Are there any clues in the above?  On C7, the "messages" log has 
nothing that I can associate with the failure.