The only solution after trying many suggestions was to simply restart the "vz" service (definitely not preferable).
Even doing an ifdown and ifup for venet0 did not help.
ifup venet0
Bringing up interface venet0:
Configuring interface venet0:
net.ipv4.conf.venet0.send_redirects = 0
RTNETLINK answers: Network is down
Some errors from log:
CPT ERR: d2dc60........
It sounds like this is corrected in later versions of the OpenVZ kernel but Iam not sure, it may also be that a much newer kernel is needed and Centos may not have a recent enough kernel.
*Debain 7.0 however does work fine as a temporary fix or work around.
Debian 8 OpenVZ no IP and networking not working:
lo Link encap:Local Loopback
 ........
If you move your hard drive(s) around to other computers/servers, you'll find that your eth0 keeps getting higher, the first time it will become eth1 and then eth2 etc and even higher if your server has dual or quad NICs. The reason is that udevd basically assigns eth0 tot he first NIC it finds and remembers it, if it encounters a NIC with a differentMAC, it assigns it one higher (eg. eth1).
See the example below, I have eth2 now so how doI fix it?........
Adding IP address(es): 192.168.5.8 192.168.5.9
Setting CPU units: 1000
Error: undump failed: Invalid argument
Restoring failed:
Error: iptables-restore exited with 2
Error: Most probably some iptables modules are not loaded
Error: rst_restore_net: -22
Container start failed
Stopping container ...
Container was stopped
Container is unmounted
Error: Failed to undump VE
Resuming...
vzquota : (erro........