TG585v8 and Bonjour

[#1]

On my network I have a desktop PC and a network printer connected to the router by ethernet cable.
The printer is Bonjour (mDNS / DNS-SD / ZeroConf) compatible.
The desktop PC running a DNS-SD browser can 'discover' the printer without problem, yet any device connected wirelessly to the router seemingly cannot.  I have tried an iPhone, an Android device, and a Windows based PC with the same result on each.
The router is running 8.2.7.8 software.
With exactly the same network configuration, but using my previous ISP's router (which was a rebadged TG585v7), Bonjour worked fine and the iPhone could print... which leads me to think that it is an issue with the (configuration of the) PlusNet router.
According to Wikipedia, the mDNS Ethernet frame is a multicast UDP packet to:
    MAC address 01:00:5E:00:00:FB
    IPv4 address 224.0.0.251 or IPv6 address FF02::FB
    UDP port 5353
As Bonjour is only used to discover devices on the local network, I should not need to expose port 5353 to the wider internet and adding a new Application rule to forward 5353 does not work.
Any other ideas?

[#2]

is uPnP enabled?

[#3]

Yes UPnP is enabled; My Network Places on the desktop PC, shows two entries for the router and one for the printer (which is also UPnP compatible).

[#4]

Hi notyetanotherid,
I've asked our hardware specialist to see if he can shed any light on this and he can't off the top of his head but said he'll do some testing this afternoon - if he gets a chance - or Monday if not.
Jojo

[#5]

Your question about UPnP prompted me to try enabling it on the wireless laptop PC, at which point the Bonjour browser there could also 'discover'  the printer, so I am guessing that the Bonjour browsers for Windows use both/either mDNS or UPnP to discover compatible network devices...
As such the desktop PC is probably 'seeing' the printer via UPnP, rather than mDNS and so my initial note about the problem only existing with wirelessly connected devices would appear to be slightly off the mark.
If I get some time I might try disabling UPnP on the desktop PC to see if the DNS-SD browser can no longer see the printer to confirm this theory.
Thanx Jojo for your time.

[#6]

You're welcome. Let us know how you get on

[#7]

How very odd?  Now all the devices (although iPhone not available to check) appear to be working correctly with or without UPnP!
I have not changed any settings and the Router has not re-started.  Weird.
Shame I have wasted a couple of days looking for solutions to this, probably never know why it wasn't working...

[#8]

That's technology for you. Give us a shout if you have any more questions.

[#9]

I think, but can't be certain, that once all devices have been discovered you can turn off uPnP and things still work until next time you make a change or DHCP re-issues (or can't) any expired IP addresses to another device.