OPNsense Forum

English Forums => 25.7, 25.10 Series => Topic started by: Evert on February 10, 2026, 01:59:08 PM

Title: [solved] System: Settings: General - unique DNS server required?
Post by: Evert on February 10, 2026, 01:59:08 PM
Hi,

We're in the process of setting up WAN failover (switch to 5G when/if the fibre connection craps out)
.
Until now we have
DNS server = 127.0.0.1
Use gateway = none
on System: Settings: General under 'DNS servers'.

However, the help text says: 'When using multiple WAN connections there should be at least one unique DNS server per gateway.'

What does that meen in practice? Or Does this only apply when using the multiple WAN connections simultaneously?

Should I have 2 entries, one for each gateway? Or can I leave this setting unaltered?
Title: Re: System: Settings: General - unique DNS server required?
Post by: Patrick M. Hausen on February 10, 2026, 02:33:36 PM
You can keep 127.0.0.1 and let Unbound (? probably) do its recursive thing using both WAN links according to the current routing table and state of the links.
Title: Re: System: Settings: General - unique DNS server required?
Post by: franco on February 10, 2026, 02:38:47 PM
Yes, you only need this when you already have manual servers listed there. DNS servers (and monitoring IPs) should not overlap between gateways. This ensures that each DNS server stays on its own WAN connection. The underlying cause is that host routes are set up for each one and you cannot connect the same IP over two different gateways.


Cheers,
Franco