OPNsense Forum

Archive => 18.1 Legacy Series => Topic started by: sirio81 on March 29, 2018, 12:19:36 pm

Title: Multi wan: system dns and monitoring ip
Post by: sirio81 on March 29, 2018, 12:19:36 pm
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

Quote
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.
Title: Re: Multi wan: system dns and monitoring ip
Post by: mimugmail on March 29, 2018, 12:25:52 pm
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 ;)
Title: Re: Multi wan: system dns and monitoring ip
Post by: sirio81 on March 29, 2018, 03:13:56 pm
Thank you for you reply.
I'd suggest to change the documentation then:

Example configuration (https://wiki.opnsense.org/manual/how-tos/multiwan.html#example-configuration)
Quote
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?
Title: Re: Multi wan: system dns and monitoring ip
Post by: mimugmail on March 29, 2018, 03:54:20 pm
Indeed, but for the record, this is my own opinion. I never tried this out since it's not really sane
Title: Re: Multi wan: system dns and monitoring ip
Post by: sirio81 on April 09, 2018, 03:49:58 pm
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
Title: Re: Multi wan: system dns and monitoring ip
Post by: mimugmail on April 09, 2018, 05:41:19 pm
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
Title: Re: Multi wan: system dns and monitoring ip
Post by: sirio81 on April 11, 2018, 03:25:21 pm
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.