Trouble whit OPenVPN and routes

NethServer Version: 7.9
Module: OpenVPN

Good morning friends.
I have a difficulty with the following, I have a different DHCP server than Nethserver on my LAN, the Nethserver I am using for services such as OpenVPN among others; The fact is that the services that I have on my LAN such as APACHE services and others, have the gateway of the DHCP server, therefore the people who connect to my VPN do not have these services, they are unreachable.
I would think that I would have to establish rules in the OpenVPN configuration, exactly in the box that says “Custom routes”, but I have tried different formats and I always get an error.
I would appreciate your help.

I assume the DHCP server is also the gateway of your network and your NethServer has just one green interface. In this case you need to set a static route on your router.

If you can’t set a static route:

I think using OpenVPN custom routes is wrong in this case but to answer your question, you just need to enter the CIDR like 10.0.15.16/32

From the docs:

CustomRoutes : a comma separated listed of CIDR to be pushed as extra routes to VPN clients

I really have two different accesses, one through the nethserver and the other through a sonicwall; I am using the nethserver temporarily only for the VPN, so the clients that connect to the VPN from the Nethserver do not have access to the services, I imagine that the gateway of these services is anchored to the SonicWall and I don’t see an option where it can change the gateway of my VPN clients.

Did you try to add a static route to the sonicwall to route the VPN network to the Nethserver?
This way the Sonicwall knows about the VPN and sends the packages to the NethServer and it should work without changing gateway settings on clients.