OPNsense Forum

English Forums => 25.1, 25.4 Production Series => Topic started by: Winpeg on March 07, 2025, 11:13:40 AM

Title: [SOLVED] Gateway Monitoring causes IPv4 to go offline, but IPv6 works fine
Post by: Winpeg on March 07, 2025, 11:13:40 AM
Hi,

I followed a tutorial and everything was working fine until I enabled Gateway Monitoring as instructed (from 18:30 in this video:Link (https://www.youtube.com/watch?v=Yb7JdIFriKI)). After that, IPv6 shows as online, but IPv4 shows as offline.

As a temporary fix, I changed the IPv4 monitoring IP to 1.1.1.1, and now IPv4 shows as online. However, I don't believe this actually solved the underlying issue.

It would be nice to have Gateway Monitoring working properly, so I'd prefer to keep that feature enabled if possible. Has anyone else had this problem? Is there a better solution to get this feature working correctly?

Thanks!
Title: Re: Gateway Monitoring causes IPv4 to go offline, but IPv6 works fine
Post by: Patrick M. Hausen on March 07, 2025, 11:25:18 AM
Is your gateway "pingable"? Some ISPs or hosting environments don't answer ICMP echo. In that case you simply cannot monitor the gateway itself.
Title: Re: Gateway Monitoring causes IPv4 to go offline, but IPv6 works fine
Post by: Winpeg on March 07, 2025, 11:36:24 AM
That might be possible. But why does IPv6 work without any issues then? Is using 1.1.1.1 for pinging a good alternative, so I can at least monitor something?
Title: Re: Gateway Monitoring causes IPv4 to go offline, but IPv6 works fine
Post by: Patrick M. Hausen on March 07, 2025, 11:39:40 AM
That all depends on the setup of the particular gateways. Nothing you or OPNsense can change.

Do you have multi WAN? If you have only a single uplink, gateway monitoring does not provide much value, IMHO. I mean, either the line is up, so will be the gateway - or it isn't.
Title: Re: Gateway Monitoring causes IPv4 to go offline, but IPv6 works fine
Post by: Winpeg on March 07, 2025, 01:00:05 PM
I only have a single WAN connection in use, so that makes sense. In that case, it seems like gateway monitoring might not add much value for me.

Thanks a lot for your help, I really appreciate it!