Fresh Install, LXC Container Networking doesn't work...

Hello,

I have some similar problem with network. To be more specific, I cannot change netmask inside LXC container CentOS 7/8. Is it possible to set/change netmask with pct command? If I change netmask in file /etc/sysconfig/network-scripts/ifcfg-eth0 and run systemctl restart NetworkManager.service nothing happend. Even If I restart LXC container netmask value stays the same as before. Any idea? Thanks.

Regards,