Add PTR and NS Records to DNS Resolver possible?

kolpinkb · Sep 29, 2017, 12:25 AM

So, I was interested in the product too. I have it half working, meaning that two of the DNS requirements are met and only the PTR records remain to be configured. However, apparently those are only needed for iOS and MacOS and not Android. Yet, when I tried to discover the printer on Android nothing shows up. The following entries I added to Unbound Resolver's custom options field:

server:
local-zone: "example.com." transparent
local-data: "mobility-print-host.example.com. A 192.168.71.3"
local-data: "pc-printer-discovery.example.com. NS mobility-print-host."

I'm not sure how important the periods are at the end of each subdomain. Whether its "mobility-print-host." or "mobility-print-host" seems to work just fine in Mobility Print's eyes.

Working on the PTR records now and will update if I get anywhere.

![papercut ng mobility print dns.png](/public/imported_attachments/1/papercut ng mobility print dns.png)
![papercut ng mobility print dns.png_thumb](/public/imported_attachments/1/papercut ng mobility print dns.png_thumb)

trentuk · Oct 2, 2017, 9:54 AM

Hi all,

I'm trying to get Mobility Print working with DNS Resolver too but without success, here are my custom options, all seem to be correct & present when doing a lookup from a client but I still can't see any printers in the Mobility Print app on Android or from any Apple iOS/OSX devices.

–-------------------------------------------------------------------------------------
server:
local-data: "b._dns-sd._udp IN PTR pc-printer-discovery"
local-data: "lb._dns-sd._udp IN PTR pc-printer-discovery"
local-data: "_ipps._tcp IN PTR pc-printer-discovery"
local-data: "pc-printer-discovery IN NS lipa-printers.mydomain.removed"
local-data: "lipa-printers.mydomain.removed IN A 10.2.1.5"

Just to be clear, I've removed my actual domain and replaced with 'mydomain.removed'

Any thoughts, suggestions, offers of moral support gratefully received! ;)

johnpoz · Oct 2, 2017, 10:18 AM

"'mydomain.removed' "

What is the domain.. Did you set this zone as transparent? Can not help you people your going to obfuscate and ask why it doesn't work.. My guess is the domain actually resolve on public and its looking for something you didn't put in so it gets back NX..

If all the stuff you put responds when you query unbound.. How is unbound not doing what you told it to do?

b._dns-sd._udp IN PTR pc-printer-discovery
lb._dns-sd._udp IN PTR pc-printer-discovery
pc-printer-discovery IN NS print-server-host
print-server-host IN A XXX.XXX.XXX.XXX

I don't see any . periods on the end of your entries..

What I would suggest is connect them for the setting up in unbound. Keep in mind unbound is not really meant to be an authoritative dns..

This is suppose to be a delegated domain.. So what domain are you using local? yourdomain.com? what??

Says right on their site
"The name of the search domain(s) for your devices (eg. Android phone, Chromebook)"

So what FQDN are you using for pc-printer-discovery ??? Its suppose to be pc-printer-discovery.yourdomain.tld and your client is suppose to be using a search suffix to find that record!!!

doktornotor · Oct 2, 2017, 10:18 AM


local-data: "b._dns-sd._udp IN PTR pc-printer-discovery"
local-data: "lb._dns-sd._udp IN PTR pc-printer-discovery"
local-data: "_ipps._tcp IN PTR pc-printer-discovery"

Dafuq?!

johnpoz · Oct 2, 2017, 10:19 AM

Exactly!!!

doktornotor · Oct 2, 2017, 10:24 AM

@OP: Here's some valid example of PTR:


local-data-ptr: "192.0.2.1 foo.example.com"
local-data-ptr: "2001:db8:a:b:c::1 foo.example.com"

johnpoz · Oct 2, 2017, 10:34 AM

Nope they want PTR setup for b._dns-sd._udp

I have downloaded the damn product they have a 40 day trial… I have to go out for my morning walk.. And then work.. But will try and get it setup today so I can screen shot exactly how to get it working with the domain your using as your search domain.. And that their papercut ng interface shows it all green, etc. And you can print from some mobile client..

doktornotor · Oct 2, 2017, 10:38 AM

AFAICT this shit wants/needs mDNS/Zeroconf and messing with Unbound will do zero useful work there. Perhaps look at Avahi instead.

Junk.

kolpinkb · Oct 2, 2017, 11:55 AM

You can do either DNS records or mDNS. I tried the mDNS discovery option in PaperCut NG Mobility print and my printer does show up in their Android app but I can an internal server error. Also, I found the avahi daemon to crash intermittently with default settings.

Would much prefer to get the DNS PTR records working.

trentuk · Oct 5, 2017, 9:25 AM

Thanks for offering to have a look at this johnpoz, very much appreciated!

This site is using split DNS, by this I mean they're using the same domain internally as externally, thus you're probably correct that something is missing from the DNS config in pfSense and the Mobility Print client is then looking at the public DNS to find it and then receives NX.

I've asked the IT Director if I can post the domain name here but they would prefer not to, therefore could we use 'yourdomain.ltd' whilst discussing the configuration?

pfSense version: 2.3.4-RELEASE-p1

System - General Setup - Domain: yourdomain.ltd

DNS Resolver - System Domain Local Zone Type: Transparent

Client DNS Suffix is: yourdomain.ltd

Given the above information, would you suggest something along the following lines in DNS Resolver - Custom Options:

b._dns-sd._udp.yourdomain.ltd. IN PTR pc-printer-discovery.yourdomain.ltd.
lb._dns-sd._udp.yourdomain.ltd. IN PTR pc-printer-discovery.yourdomain.ltd.
pc-printer-discovery.yourdomain.ltd. IN NS print-server-host.yourdomain.ltd.
print-server-host.yourdomain.ltd. IN A XXX.XXX.XXX.XXX

Many thanks in advance …

Derelict · Oct 5, 2017, 9:36 AM

I think OP really wants to configure SRV records for that, not PTR records.

I would say the confusion knob is turned up to 11.

johnpoz · Oct 5, 2017, 9:47 AM

I have downloaded the software, and yeah something is not right that is for sure with their instructions.

Sorry to say I will most likely not get back this for a few days.. I got new internet at home 500/50 and it consuming my interest ;)

What I noticed was didn't even see the client doing a dns query for the PTR.. I think the current mdns that was on the segment was confusing it, etc. I will have to turn off the mdns on the printer, etc. And need to run the mobility client on different machine than the papercut ng, etc.

trentuk · Oct 5, 2017, 9:55 AM

Hello Derelict,

@Derelict:

I think OP really wants to configure SRV records for that, not PTR records.

I would say the confusion knob is turned up to 11.

The software vendor specify a requirement for the following records:

;–-------------- Mobility Print records --------------

b._dns-sd._udp IN PTR pc-printer-discovery
lb._dns-sd._udp IN PTR pc-printer-discovery
pc-printer-discovery IN NS print-server-host
print-server-host IN A XXX.XXX.XXX.XXX

;--------------- End of Mobility Print records ---------

https://www.papercut.com/products/ng/mobility-print/manual/how-to-setup/step-2-configuration/discover-your-printers-using-dns/

Which is possibly the cause of the confusion knob being turned past its recommended level ;)

trentuk · Oct 5, 2017, 3:39 PM

Hello johnpoz,

No problem, glad I'm not the only one struggling with this ???

Enjoy the new connection, hopefully see you back here once you've downloaded the entire internet at blisteringly fast speeds ;)

kolpinkb · Oct 5, 2017, 2:33 PM

Thanks again johnpoz,

This configuration has many of us perplexed.

Have fun with the new 500/50 connection. I'm sure the increased upload is the best part.

Derelict · Oct 5, 2017, 4:38 PM

The software vendor specify a requirement for the following records:

;–-------------- Mobility Print records --------------

b._dns-sd._udp IN PTR pc-printer-discovery
lb._dns-sd._udp IN PTR pc-printer-discovery
pc-printer-discovery IN NS print-server-host
print-server-host IN A XXX.XXX.XXX.XXX

;--------------- End of Mobility Print records ---------

The software vendor's confusion knob is turned up to at least 12. That makes no sense at all. PTR records do not have names on both sides. They are used to lookup a name when all you have is an address, like 198.51.100.101.

luckman212 · Oct 5, 2017, 4:46 PM

They look like SRV records…. at least the left-hand side.... maybe you can "sniff" the correct format from a working setup using some form of dns-sd -Z

kolpinkb · Oct 5, 2017, 5:04 PM

I think the software is looking to be a delegation server for a specific subdomain.

Base domain: example.com
Delegation server: mobility-print-host.example.com
subdomains to delegate: xxxxprinter.b._dns-sd._udp.pc-printer-discovery.

???

Derelict · Oct 5, 2017, 5:10 PM

Unless the LHS of those PTR records is supposed to be replaced with at least part of an IP address, to be completed with .in-addr.arpa., they are nonsense.

Or we're going to need a lot more information about what it is they are trying to do.

kolpinkb · Oct 5, 2017, 5:11 PM

The configuration example on their website (that we've all shared here) is specifically for BIND. Not sure if it translates 1:1 for Unbound.