This often happens if you are adding a secondary route, especially with Linux source based routing.
ip route add default via 10.10.10.254 table 10
RTNETLINK answers: Network is unreachable
If that happens you will probably find that it is unreachable because your NIC does not have an IP in the 10.10.10.0/24 range so just assign an IP in that range to your NIC and try again.
eg. ifconfig eth0 10.10.10.254 netmask 255.255.255.0 up........
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.
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........