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EMBARRASSING UPDATE:
I rebooted my laptop and it solved the problem. D'oh! Thanks for your thoughtful answers.

I’m using OS X 10.10.2 (14C109). I’m not sure when this changed, but certainly a couple of months ago I was able to use the “Go” menu on my desktop to browse to my laptop over my Local Area Network (LAN) and move files back and forth by drag and drop.

Yesterday I tried to do so and cannot see the laptop. If I type in its IP address on the LAN, e.g., smb://192.168.0.195, I can connect to it and it works fine, so sharing is enabled and working and the laptop is visible. And of course I can use SCP from the command line to do the same. But I do not see it when I try to “Browse” and looking up the IP address is not really what I want to have to do each time as DHCP changes it around.

Isn’t Bonjour supposed to make this easier? Finding the laptop’s IP address is a bit of a hassle. Edit: I can see my desktop from my laptop when I "Browse." Just not the other way around...

If I run arp -a on my desktop, it does not list my laptop's IP address but does very quickly lists most of my other devices on my LAN. If I run arp -a on my laptop it is very slow and shows a WAN address that is not any that I can recognize, starting with 169.254, along with a couple more I do recognize. Odd.

Rich
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3 Answers3

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I am also using OS X 10.10.2 and it appears to work fine over here.

First, I would make sure that you are all on the same subnet. (Maybe also share the local network IPs and subnet masks you see for the relevant computers). You mentioned that the DHCP keeps changing things around and from the IP you provided, I could assume there are a lot of machines in your network - maybe more than 255 - but of course I am just guessing here ?

You also want to make sure that in the Security & Privacy control section of the System Preferences, you check the Firewall > Firewall Options... Make sure Stealth mode is not enabled here for all the machines you want to connect to (and confirm that incoming connections are not blocked, but this shouldn't be the case, since you can still connect to your shares, when using the actual IP). Also check the Sharing section and restart all the services there. At the top underneath the Computer Name it should also tell you which name your computer has in the local network (usually MyComputer.local).

If all this doesn't bring up any solutions, can you maybe configure the DHCP yourself? I would then set a reserved address for all computers you want to connect to and they could then always be reused from the Recent or Favorites section of the Connect to server dialogue.

Chris
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This is typically caused by misconfigured or buggy networking devices that break multicast and thus break Bonjour, which relies upon multicast.

See also: Why do some WiFi routers block multicast packets going from wired to wireless?

Here are the common things to check:

  1. If you have more than one router-capable device on the network, make sure that only the one that directly connects to your broadband ISP connection is actually acting as a NAT gateway router. Other NAT/router-capable devices on your network should have their NAT/router/DHCP-server functionality disabled; that is, they should be configured to just transparently bridge traffic between wired and wireless. If those other devices are configured to act as NAT gateways or routers, then they're acting as multicast borders, separating your home LAN into multiple separate LANs that multicasts can't pass between.

  2. Make sure you don't have your Wi-Fi APs set to block multicasts or set to isolate wireless devices from each other.

  3. Make sure you don't have your wireless multicast rate set too high. It has to be low enough that every device on your network, no matter how old or far away, can receive multicasts reliably.

  4. Run a test with wireless security completely disabled. Buggy implementations of wireless security protocols often break multicasts. The trickiest one to implement is what's known as "WPA2 mixed mode", where both WPA2's AES-CCMP protocol and original WPA's TKIP protocol are enabled at the same time. This causes most clients to use the AES-CCMP cipher and one key for unicasts, and a different cipher (TKIP) and a different key for multicasts. I've seen lots of clients and APs fail to get this right. If the "no security" test fixes multicasts, try WPA2-only mode. Most people don't have any WPA/TKIP-only equipment on their networks anymore anyway. Pretty much anything made in 2003 and later does WPA2/AES-CCMP.

Community
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Spiff
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EMBARRASSING SOLUTION: I rebooted my laptop and it solved the problem. D'oh! Thanks for your thoughtful answers.

Rich
  • 255