I only remember adding the one starting with 6, to advertise the 192.168.1.1 as a dns server, but I don’t remember adding the one starting with 3 or 15, what do they do?
3 == Router (Default Gateway): I do not think you need to set this explicitly. I believe this should be by default set to the IP of respective interface.
6 == Domain Server, you do not need to set this explicitly most of the times. You may want to set this explicitly in more advanced setups, e.g. you want to use dnsmasq as DHCP server but not as DNS server (e.g. you use knot or unbound for DNS). And even then you probably want it set to 0.0.0.0 which is internally automatically replaced by the IP of the interface. Sometimes you may want to set this to some public DNS (e.g. 1.1.1.1 or 8.8.8.8) if you do not want client to use this router as DNS server.
15 == Domain Name, localdomain, again I do not think you need to set this explicitly. I think you set this in Network>DHCP DNS Settings>Local Domain.
If your router's IP is 192.168.1.1, 3 and 6 are unnecessary.
And lan is the [DHCP announced] domain by default configuration in OpenWrt.
I’d be worried:
Either:
I’m making changes that I, both, do not remember and cannot fathom why.
or
Someone else made the edit.
Is OpenWrt doing this now?
Everyone is replying as if this is expected.
Did something change?
Is this a new feature?
I cannot conceive why would somebody explicitly set the option 3 other than blindly listening to hallucinating LLM.
I’m relieved we are speculating: I thought I’d missed a paradigm shift.
@mahos Any, simple, explanation how you did not put those in there?
?
I'm replying as if the user added it. I'm just informing the user it was unnecessary.
OK maybe just maybe is some more advanced scenarios you do it: e.g. you want your openwrt to be DHCP server but set "Default Gateway" to some other router.
Question for @mahos is the value of the option same as the IP of the lan iface?
I was bouncing you because you seemed so comfortable; I thought I’d missed OpenWrt making it’s own changes.
Because, “I did not put two of those in there” getting replies like “well, they do this and that does that” ‘normalized’ something (not normal to me) and I trusted you would/could set it straight.
Wow...if the user didn't add 2 (of the 3) of those DHCP Options, that would be a concern.
Perhaps the user ran a UCI-based script?
Yes it was Iranian double mosad agent from North Korea with the help of Claude.
Chill. Dude. I bet the user just blindly followed yet another YouTube dude two years ago and forgot about that. They are talking about an dhcp option with default values, and not a random python script and suddenly a python2.7 environment.
Now I’m not so excited about, wild, speculation…
I would suggest that we all wait for the OP to respond.
- The information provided by @mvasek is correct in terms of what the options are.
- What @frollic and @lleachii stated is also correct in a (near) default installation -- these options are not necessary to set unless they are pointing somewhere else.
- There are scenarios in which they may need to be set manually, such as environments with changes to the behavior of dnsmasq (adguard, DoH/DoT, etc.).
- Some installation/configuration scripts or tutorials available on the internet for the above (i.e. adguard, DoH/DoT, etc.) may add those options with or without the user realizing it.
When the OP responds, we can get more information about the specific situation.
for everyone asking, I added adguard home while sleep deprived, so I wasn’t focus while carrying the instructions of https://openwrt.org/docs/guide-user/services/dns/adguard-home#setup the setup script there adds those, I just didn’t notice, don’t worry openwrt doesn’t add those on it’s own, @psherman got it right, it’s the 4th possibility they listed
4th option, but given the 3rd one is involved making adguard dns the default 53 & moving dnsmasq to 54 are those still needed, or should I just remove them?
If things are working properly, no need to change anything. The additional options will not cause problems, even if they are not necessary (I am pretty sure that option 6 is required in your situation, options 3 and 15 may or may not be necessary, but are benign if not actually necessary)
It, kind of, did.
And it did it with your edit in the middle.
Which, if the install just overwrites the .cfg, makes sense now but not in the context of “I edited the one in the middle”; because LuCI does not work like that..
Glad it’s resolved.
In wiki history I see you added the options 3 and 6, to the adguard guide in revision "[Setup] fix missing DNS option settings.".
Why was the option 3 added there? Should not be that by default set to the IP of the respective interface?
I think you were right to set the option 6, AFAIK if the DNS functionality of dnsmasq is turned off (or maybe moved to non-standard port) then dnsmasq stops setting the option 6 automatically.
Just tiny improvement suggestion: I think it would be better to set it to 0.0.0.0 instead of the current IP of the respective interface. The special value 0.0.0.0 should be internally interpreted as "current IP of the respective interface". I don't know maybe this was not how it worked back then in 2022.
I know about the 0.0.0.0 special semantic because I recently switched to unbound because I wanted DNS64. I found it here: https://forum.turris.cz/t/running-ipv6-only-or-ipv6-mostly-network-on-turrisos/19521