Multi wan: system dns and monitoring ip

[sirio81]

Hi, I was wondering if using the same ip for dns and monitoring ip may cause problems.
I ask this because I'm testing pfsense as well and there are concerns about routes and monitoring ip.
https://forum.pfsense.org/index.php?topic=145739.msg792964#msg792964

Setting a particular address for a monitor causes the system to static route it through a particular gateway. Setting one of the system DNS servers to a particular gateway also causes the system to static route it. If you are not careful, you can cause the monitor to flap between two gateways. From your description, it sounds possible you have encountered this problem.

I know OPNsense share very little with pfsense but the logic may be the same.

[mimugmail]

You will get errors in the log because the system will set a route for DNS (separate script) and also for monitoring (separate script). I'd not do this! There are more public dns servers that 8.8.8.8 and 8.8.4.4

[sirio81]

Thank you for you reply.
I'd suggest to change the documentation then:

Example configuration

As DNS’s and monitor ip’s we will utilize google’s DNS services 8.8.8.8 and 8.8.4.4

Do you agree?

[mimugmail]

Indeed, but for the record, this is my own opinion. I never tried this out since it's not really sane

[sirio81]

Btw, the loop problem I encountered on pfSense is not related to DNS / Monitoring ip.
I still don't know what is causing it.
Right now I'm running OPNsense

[mimugmail]

If you have a loop and your Switch  goes crazy you have something wrong with cabling. No OS without STP will help you there. Check cabling

[sirio81]

No cable has been moved.
Right now everything is running with the same cable setting but with OPNsense instead of fpSense.
Anyway, this isn't a OPNsense related issue.
I'll report back if the same issue will show-up with OPNsense.
Thank you for the support.