Two computers don't see eachother on Bonjour

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Two computers don't see eachother on Bonjour

Hi Mac gurus,

I have one Macpro and one Macbook Pro on the same network (same subnet), and they can't see eachother with Bonjour. Both can see other computers on the same subnet without any issue. Both run OSX 10.6.8.

I used BonjourBrowser on each of them and confirmed they can't see each other (no entry whatsoever on any of the services), but can see other computers. I used Wireshark on the Macpro and confirm it receives Multicast packets from the Macbook Pro (Bonjour packets on port 5353), but somehow it doens't pick them up.

I can ping between the 2 using their respective IP address, but not via the [hostname].local (no name resolution on these).

I even tried to plug an ethernet cable between the two and set up a manual 192.168.0.0/24 subnet with no luck.

One think to note is that I'm logged in on both machines with the same identity (coming from an LDAP server of the company).

Anyone can help ?

Greg

Mac OS X (10.6.8), Bonjour protocol

Posted on Aug 31, 2011 2:14 AM

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Answer 1

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MrHoffman

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Aug 31, 2011 5:42 AM in response to Kounch

Do either of these hosts have multiple network controllers?

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Answer 2

Linc Davis

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209,547 points

Aug 31, 2011 6:14 AM in response to Kounch

Disconnect both machines from the network and connect them to each other with an Ethernet cable. Does Bonjour work then?

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Answer 3

Kounch Author

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Aug 31, 2011 6:19 AM in response to MrHoffman

The Mac pro has 2 controllers, only one plugged in

The Mac book Pro has one active airport, and one ethernet cable, both on separate subnets.

But I actually found the solution : Multicast was disabled on my machine by corporate security. So my machine was able to see other machines, but not able to Multicast its presence on Bonjour.

To re-enable it I had to edit this file and remove the NoMulticast instruction. Then I rebooted and it worked.

/System/Library/LaunchDaemons/com.apple.mDNSResponder.plist

This basically removes the Multicast limitation and instantly allows the machine to Multicast its presence on Bonjour !

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