OVH - cannot set wan interface default gateway

ICTProxserver · Apr 30, 2025, 7:25 AM

With OVH it is often very inconvenient when an extra IP address is used. In this case the pfsense does not accept the gateway during installation. So how do you get this information to work?

The settings below are not accepted during installation following error,
cannot set wan interface default gateway.

IPv4 Address 5.39.98.xx /32 = 255.255.255.255
Default Gateway 94.23.217.xxx

With a Windows 10 installation, for example, these settings do work. Apart from the fact that Windows also indicates that this setting is incorrect. OVH simply has a strange way of routing, which it is not in this case. But linked to your current IP

stephenw10 · Apr 30, 2025, 2:24 PM

You have to set the advanced gateway option: Use non-local gateway because, as you say, OVH have their special way of doing things that ignore normal conventions! A gateway outside the WAN subnet is not valid except for ptp connections. But.... OVH.

https://docs.netgate.com/pfsense/en/latest/routing/gateway-configure.html#advanced-gateway-settings

ICTProxserver · Apr 30, 2025, 2:24 PM

@stephenw10 Thanks for the response, only I have not yet run the web interface I am in the setup installation. Can I go to the Command line and enter a command via the shell that activates this action? In the meantime I have installed OPNsense. Works too but Pfsense has more other options.

stephenw10 · May 1, 2025, 7:25 AM

No, the input validation will prevent you entering a bad gateway at the initial setup like that. You would have to either connect to the webgui from the LAN or add a gateway manually as a temporary workaround to get WAN access/

ICTProxserver · May 1, 2025, 7:25 AM

@stephenw10

Am I understanding this correctly so as an example use a non-existing gateway which is on the same network segment. Then via the kan gui adjust this to the correct (OVH gate) For now I have installed a
fork of pfSense namely OPNsense running. This system went a bit smoother here with the strange gateway of OVH. I want to evaluate both systems. OPNsense is also not bad. Both systems will have their pros and cons. Thx for youre reply

stephenw10 · May 1, 2025, 12:42 PM

Just set no gateway or set the WAN to DHCP at the initial assignment. Then access it via the WAN and enable the non-local gateway option.

If you really have to you could probably set that at the command line but I'd have to go through and check.