This is a custom issue that we have to deal with… Our host provider is OVH and its common for your new ips to be separate from your gateway ip network… Nethserver has a very hard time with this…
We have been really trying to work with this by inserting the proper info in the web front end however it doesn’t seem to stick…
Right at this moment I am in the middle of a medical transport for a dr appointment I have when I get home I will fire up proxmox and try to install the beta…
I am having the same issue with this distro as the last one… It does not like to connect to the internet side of the world… Here is a screen shot… https://1drv.ms/i/s!Ann6Dvc7oI7eng8ZAv0WPQNawl4b
Some of this i can’t talk about on the thread so if your open to a private message i will be able to share maybe a little more on whats going on with our setup…
As @alefattorini said and what the red message show, in the Network address field you must use the CIDR format of the network: 192.99.90.0/24, as example.