Add PTR and NS Records to DNS Resolver possible?
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I just got feedback from Papercut support:
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(PaperCut)I apologize but presently we don't have a documented method to set up the DNS records for Mobility Print using Unbound with PFSense. However, I do want to point out that other customers with PFsense routers that want to use DNS Discovery for Mobility Print have reached out to us to see if this is something that can be achieved. I previously created a to-do item in our feature tracking system for our developers to take a look at whether this is feasible. I have also linked this support ticket to the feature request so that we can notify you by email in the future if this is something we are able to document. I can't say when we would be able to answer this however.
In the short term I would also like to point out that there are several other methods for setting up Mobility Print, even for environments with multiple subnets and VLANs. For example, you can connect multiple network interfaces to your Mobility Print server and allow it to broadcast mDNS to advertise printers to clients in each network. Alternatively if your router supports Bonjour Forwarding, then you could set it up to allow mDNS traffic to pass from your server VLAN to your client VLANs.
Let me know if you have any questions at all or if you would like to discuss some of the alternate methods I mentioned above.
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You could most likely just use the avahi package with pfsense.. It does mDNS/DNS-SD
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DNS Resolver Custom Options:
server:
local-zone: "example.com." transparent
local-data: "b.dns-sd._udp IN PTR pc-printer-discovery.example.com."
local-data: "lb.dns-sd._udp IN PTR pc-printer-discovery.example.com."
local-data: "pc-printer-discovery.example.com. IN NS print-server-host.example.com."
local-data: "print-server-host.example.com. IN A 192.168.224.17"Test queries:
[2.4.2-RELEASE][root@pfSense-b.example.com]/var/unbound: dig +short +search +domain=example.com @localhost PTR b.dns-sd._udp
pc-printer-discovery.example.com.
[2.4.2-RELEASE][root@pfSense-b.example.com]/var/unbound: dig +short +search +domain=example.com @localhost PTR lb.dns-sd._udp
pc-printer-discovery.example.com.
[2.4.2-RELEASE][root@pfSense-b.example.com]/var/unbound: dig +short +search +domain=example.com @localhost NS pc-printer-discovery
print-server-host.example.com.
[2.4.2-RELEASE][root@pfSense-b.example.com]/var/unbound: dig +short +search +domain=example.com @localhost A print-server-host
192.168.224.17From there it is up to the client to ask the DNS server on the mobility print server at 192.168.224.17 whatever it needs to ask about the pc-printer-discovery zone.
It looks to me like this should work. It implies the client is pointed EXCLUSIVELY at unbound (and/or a similarly-configured server) and has a correct search domain set for "example.com".
I did not try to get a Mobility Print environment working.
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Note that unbound agrees with my prior assessment of the wackiness of the name-keyed PTR records. They have a local-data-ptr option for setting PTR records:
local-data-ptr: "IPaddr name"
Configure local data shorthand for a PTR record with the reversed
IPv4 or IPv6 address and the host name. For example "192.0.2.4
www.example.com". TTL can be inserted like this: "2001:DB8::4
7200 www.example.com"If you try something like:
local-data-ptr: "b.dns-sd._udp pc-printer-discovery.example.com."
It barfs with:
The generated config file cannot be parsed by unbound. Please correct the following errors:
[1516213033] unbound-checkconf[27521:0] error: syntax error: cannot parse address: b.dns-sd._udp pc-printer-discovery.example.com.
/var/unbound/test/unbound.conf:86: error: local-data-ptr could not be reversed
read /var/unbound/test/unbound.conf failed: 1 errors in configuration file -
Where the problem is I do not believe the client follows through with looking up pc-printer-discovery.example.com.
When NS is authoritative its different - same issue with a cname in unbound. You can for sure put in a cname record.. But it doesn't follow through and finish, its up the client to follow the query when the not using authoritative ns, etc.
If the client actually does a query for pc-printer-discovery.example.com. you could just put that record in unbound directly..
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It looks to me like pc-printer-discovery.example.com is a subdomain. Those records/that zone will be found on the mobility print server itself.
At least that's what it looks like to me.
I am really not in the mood to install it and see.
It looks like the above config is what is necessary to get the records papercut say need to be there in there.
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"It looks like the above config is what is necessary to get the records papercut say need to be there in there."
Yeah went through that while back - doesn't work, because yes pc-printer-discovery.example.com is a subdomain delegation… Its hokey setup to be sure.. Trying to put these records into unbound make no sense at all.. The whole thing is designed for the authoritative NS for the domain in question which is not what unbound running on pfsense is
http://www.dns-sd.org/serverstaticsetup.html
You really should be able to get away with a domain override for the domain
_dns-sd._udp.example.com
Point _dns-sd._udp.example.com via NS record to the mobility print server let the client do whatever it wants via a domain override.
I would think it just much easier to setup avahi..
If user really wants to use this setup and run it on pfsense, then they should be using the bind package that gives them full authoritative nameserver software on pfsense - with a gui to boot to manage ;)
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Unfortunately, I already tried avahi. The mobility app under android and windows returns an error that I haven't been able to sort out with the Paperacut team.
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Then pcap the DNS traffic and see where the breakdown is.
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Can for sure make unbound answer pretty much anything that gets queried for.. But its not going to do some of the stuff an actual authoritative NS does for a zone its authoritative for, etc.
If you do a sniff and see what is queried - pretty freaking sure can make unbound answer with the answer you want for the specific query and type.
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I can confirm Avahi is not working. Just tested it.
The mobility print setup does not find any printers in another VLAN. -
love to see a sniff of these dns queries being done on your working system.. I want to see what the query and answer look like for pc-printer-discovery.example.com
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love to see a sniff of these dns queries being done on your working system.. I want to see what the query and answer look like for pc-printer-discovery.example.com
We are going to install a test environment within the next days with papercut NG/MF and mobility print.
We could give Teamviewer or VPN connection. -
K..
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@selo said in Add PTR and NS Records to DNS Resolver possible?:
Hello,
First I want to say that I'm using Mobility print with my PFSense since 6 months and everyhting's is working fine with AVAHI package and mDNS on my Mobility print server
But as Avahi package spread accross the differents VLAN I want a more secure configuration, so I start to work about switching from mDNS to DNSAs I'm not an expert, I asked Papercut a hand on this. It didn't seem possible to configure DNS with "DNS Resolver", so I installed the "BIND" package on my PFSense
On the same VLAN, the client can installed Mobility print on the windows, and launch a print job.
But now I put the windows workstation on another VLAN, and even if the record didn't changed, I can't reach my server and install Mobility printI'm still talking with Papercut team to solve that problem, I have the impression that with BIND it's working a little bit better than DNS resolver ? Maybe there is some updates on your side since 5 months ?
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I have not looked at this crap since we ended it. The way they are doing is just stupid if you ask me. They don't even seem to understand how their own product works.
Its not a difficult to manually setup dns records for airprint.. But to be honest this makes no sense to setup unless you have clients you do not control that you want to find your printer. Or shitty ass clients that do not allow for setup of the printer.
http://www.dns-sd.org/serverstaticsetup.html
Why would you not just point your client directly to the printer or the print server via their IP or FQDN that resolves.
I can print from any vlan - just point the clients to brother.local.lan = done ;) If your running bind as your authoritative ns and your main dns now for all your clients I would suggest you get with them on the correct records to place in it - for follow the info I linked too above for setting up dns-sd
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Thanks for your update.
I'm really not a DNS jedi, so I just followed the tutorial from Papercut. Since I read many things about DNS, now some things are crystal clear, other not.
So I will try your solution. Airprint was just so easy to configure for the computer who are only on the building for 2 days, instead of the installation with IP, with the proper driver, the Papercut client etc ... it's only few minutes more, but X times a week it's a lot a wasted time !
And before that I didn't use any DNS server, so there are a lot to learn and process -
Tell you what... I have some clients (ipad, iphone, etc) that pretty much need airprint to work. If I get a chance after work I will move my printer to my lan vs the secured wireless (the printer supports airprint) so a long as devices are on the same L2 they find the printer directly.
This has been on my sort of todo list for awhile ;) But since I only allow my devices to print it was just faster and easier to put the printer on that L2. My wired devices that print - for example my PC or laptops that might be on other wireless networks like guest, etc. Just point directly to brother.local.lan for the printer that resolves to 192.168.2.50.
But allowing print from my secured wifi (eap-tls) for my devices, and allowing to print on my guest might be useful I guess ;)
The dns-sd should be possible to setup in unbound.
I can setup the records from work.. But won't really be able to test until I get home and fire up ipad/iphone, etc.
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Hi johnpoz,
Printer discovery with PaperCut Mobility Print leverages the way that Apple devices natively discover printers on the network. It's meant to be zero-config for the end users, which means no entering IP addresses or server FQDNs for it to work. Admittedly, this means that there is a bit more work for the sysadmin to do though.
The way this works is that macOS and iOS clients will look for two DNS records (b._dns-sd._udp and lb._dns-sd._udp) which we forward to an NS record (pc-printer-discovery). Whereas, Windows, Android, and Chrome devices running the Mobility Print client app will just look for the NS record. This NS record in turn can resolve to the hostname or IP address of the Mobility Print.
I want to let you know that I'd be more than happy to do a remote session with you to see if there's a way to get this working with Unbound on PFSense. We've actually had few PFSense enthusiasts reach out to us to ask if we can help them, so it would be great to get a solution tested and documented.
Let me know if this is something that you're interested in, or if there are any questions I can answer for you at all.
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I don't really give 2 shits about your product... You should be reaching out to the OP that is having the hard time with this.. Not me ;)
The questions you can answer is the simple easy to understand instructions for how to make it work with unbound.. If you have had a few pfsense users reach out to you - you would think you would already have this documented on your site..
