DNS resolver stopped resolving one hostname

johnpoz

Why doesn't 127.0.0.1 answer? is unbound not actually running?

Do you not have it listening on loopback? You for sure should be able to do a query on pfsense going to loopback.

and just normal dig should do that too..

[21.05-RELEASE][admin@sg4860.local.lan]/root: dig muenchen.social

; <<>> DiG 9.16.15 <<>> muenchen.social
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 3216
;; flags: qr rd ra ad; QUERY: 1, ANSWER: 1, AUTHORITY: 0, ADDITIONAL: 1

;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;muenchen.social.               IN      A

;; ANSWER SECTION:
muenchen.social.        1414    IN      A       159.69.89.221

;; Query time: 0 msec
;; SERVER: 127.0.0.1#53(127.0.0.1)
;; WHEN: Sun Jul 11 16:17:48 CDT 2021
;; MSG SIZE  rcvd: 60

[21.05-RELEASE][admin@sg4860.local.lan]/root:

You can see there it used loopback for the query.

silmaril

@johnpoz
Not sure what's happening here, but after I woke up this morning, resolving the problematic host is working again.

pfBlockerNG is still disabled, so I don't think it has anything to do with my whitelist entry.

I'm still trying to understand the problem. What do you mean by "is unbound running"? Which options should I check here?

(Sorry, I don't have much knowledge about DNS, until now that was just something that worked fine ).

Gertjan

@silmaril said in DNS resolver stopped resolving one hostname:

pfBlockerNG is still disabled,

Was it ( pfBlockerNG ) running when you found out that muenchen.social wasn't resolving - the first time ?
Was it resolving to something like "10.10.10.1" or just nothing at all ?

silmaril

@gertjan
As far as I can reproduce it, I am pretty sure, pfBlockerNG was not running when the problem first occured.
It did not return any IP.

When testing with Network Analyzer on an Android phone, I got a SERVFAIL error, which seems strange, because usually it's NXDOMAIN if the name cannot be resolved.

Gertjan

@silmaril said in DNS resolver stopped resolving one hostname:

Network Analyzer on an Android phone

For the next time :
Use

dig muenchen.social +trace

on the console (or : easier : ssh) access.
You'll have all answers on the screen.

Or, on a PC :

nslookup

and activate the debug :

set debug=on

Now enter :

muenchen.social

and you have all the details.

I don't have android device - neither would I use such a device for these tests.

silmaril

@gertjan said in DNS resolver stopped resolving one hostname:

@silmaril said in DNS resolver stopped resolving one hostname:

Network Analyzer on an Android phone

For the next time :
Use
dig muenchen.social +trace
on the console (or : easier : ssh) access.
You'll have all answers on the screen.

That's awesome! Thanks for this hint!

Or, on a PC :
nslookup

My PC is running Linux ;-)

I don't have android device - neither would I use such a device for these tests.

It was just interesting because of this error code - but I will use dig ... +trace, if I encounter similar problems in the future.

johnpoz

btw you can install dig on your pc.. Its a MUST have for me ;)

Just install the bind package from isc and pick tools only..

here is my windows machine

C:\>dig

; <<>> DiG 9.16.18 <<>>

if linux than yeah easy as well to install dig if you don't have it.

Gertjan

For pfSense :

pkg install bind-tools

johnpoz

@gertjan didn't they make it default installed? I know I am on clean install of pfsense+ and I don't recall installing that package..

Gertjan

@johnpoz said in DNS resolver stopped resolving one hostname:

didn't they make it default installed?

I don't think so. But I can't remember.
Installed pfSense ones, version 1 ? When I was fiddling with M0n0wall. Or something like that. Seems ages (a decade ?) to me. Been upgrading since, never re installed, it.

edit :

Joined 29 Dec 2005, 21:40

Ok, more then a decade.

johnpoz

I think it is part of base install now... When 2.5/+ came out I did clean installs.. And I don't recall having to install that, and I have dig..