OSX and Windows Vista / 7 master browsers

I think I may have located the reason why Vista and 7 no longer work as the master browser, because NetBIOS has been removed from all OS's starting with Vista according to this technet article (look for the section called 'Removal of Technologies':

http://technet.microsoft.com/en-us/library/bb726965.aspx

I am assuming that mac's require NetBIOS in order to see windows computers with a windows master browser in place and probably do not support other methods that Microsoft now employs.

I have continued searching for ways to make things work but I currently have not found any that work for me, though I found a few other discussions on here and sites from googling, all of which did not make any change in my particular issue.

One more thing I should add is that while I originally thought my Tiger iMac was having the issue my Leopard macs have, but this is not the case, it is capable of acting as its own master browser and seems to do so by default. It finds all my workgroup computers, you just have to wait a little bit for it.

The lack of netbios support in Vista also explains why I cannot connect to my Vista system using Apples Screen Sharing VNC utility - I have to use the IP address but for XP machines I can use their hostname.

Greg

Yea I realized later that I was mistaken after doing more research. I have continued looking into this. There are quite a few registry settings I am looking into under HKEY LOCALMACHINE\SYSTEM\CurrentControlSet\Services\Browser and HKEY LOCALMACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer that may have an effect on the issue. One thing I have been doing is comparing registry settings between my XP, Vista and 7 machines and trying to figure out what each setting does.

Additionally I am running Wireshark on XP and Vista while each is the master browser, and right now a Cocoa analyzer on my macbook because I think the latest OSX update killed wireshark. Seems every time I get an OSX update something breaks...but thats another issue.

There is also a possibility (although I doubt it) that the failed responses are security related, so I have been looking through Gpedit.msc on all three win machines to see what I can find, but so far nothing of significance.

If anyone else has found answers please do share. At this point I am looking for specific reasons why something will fix the issue as I have seen far to many "I tried this...and then it worked!" which do not work for everyone, so they aren't real solutions.

Thanks all!
Greg

Well I have found a work around, although it is not a perfect solution, it gets the job done and it definitely works, and should work for anyone else who tries it. If anyone does happen to try it I would definitely be interested in your results. Also if anyone knows a lot more about what changed in Vista / 7 / server 2008 where they no longer respond to OSX 'smbserver' requests (explained more below) or a possible 'correct' was to resolve this I would be interested in knowing. I tested the work around by reversing the changes and repeating the steps on both my Vista and 7 systems and it worked in both cases.

I did several tests watching packet traffic with Wireshark on Vista and XP while each was the master browser. I don't know 100% why this works this way, and while I would like to share with you all the packet logs I saved, I do not know of an easy way to strip my computer name info and would prefer not to post this on the internet.

I found that OSX requests a NBSS (NetBIOS Session Service) session by a couple of different 'names' - the IP address, the network class - 192 in this case, and by something called *SMBSERVER. In the case of Windows XP it responds with a 'Positive session response' only when OSX sends the request to *SMBSERVER. In the case of Vista it returns a 'Negative session response, called name not present' to all three recipient names that OSX tries. On XP once the NBSS session is established you then see communication on the LANMAN and SMB protocols.

I found that there is a registry setting to add a NetBIOS alias that you can add to your Vista or Win7 registry under HKEY LOCALMACHINE\SYSTEM\CurrentControlSet\Services\LanmanServer\Parameters called OptionalNames - make it a string or multistring, once created open it up and put in the IP address of your master browser computer (note that you must have a static IP configured on that system because if it ever changes this work around will stop working).

After you have made the change close out of the registry and go to Start and type Services.msc in the quicksearch bar. In Services scroll down to the 'Server' service and restart it, it will ask to restart Computer Browser and Homegroup Listener (the HG Listener will only be on Win 7), just say Yes. Now you will need to refresh your network adapter on OSX, do this by unplugging and plugging back in the network cable or by disconnecting from your wireless access point and then reconnecting. After a few minutes you should see your windows machines start to show up in Finder on your Mac, it could take as long as thirty minutes for them to show up as the Master Browser builds its cache and then distributes it to other computers. The one thing that is 'bad' about this work around is that you will also see the IP address of your Windows Master Browser in your network list of Finder, this is because of the alias that was created in the registry.

Also note that if you have multiple windows systems on your network you will need to do this work around on EACH computer that you want to be a potential master browser, as well you will need to Stop and Disable the Computer Browser service on any machines you do not want acting as a master browser. Keep in mind to be careful whenever you are editing your registry, always do a full backup of the registry before making changes.

Some other things which may be important (but I did not test yet) -
1. I have my Mac's set on a 'custom' network type - go to System Preferences | Network and hit the drop down at the top called 'Locations' and go to 'edit locations' and create a new one.
2. Select your network adapter from the left and go to Advanced | WINS and type in the name of your windows workgroup. If you use both hardwire and wireless ethernet be sure to repeat this step for both adapters
3. On my Windows Vista machine I have already changed a network security setting which may prevent this from working. By default Vista will force NTLMv2 communication which causes issues trying to connect to apple computers from a windows machine. Although this should only be an issue when connecting to an OSX system FROM Vista, I did observe in doing packet tracing that an NTLMv1 session was negotiated so this may be helpful for some folks (it should not stop the computer list from displaying but may stop you from connecting to computers). Open up 'gpedit.msc' by going to Start and typing it in the quick search bar. Drill down from Local Security Policy | Computer Configuration | Windows Settings | Security Settings | Local Policies | Security Options and then look for the setting 'Network Security: LAN Manager authentication level' - open it up and change the drop down to 'Send LM & NTLM - use NTLMv2 session security if negotiated' and click Apply. Note that in Win7 this setting is disabled by default.
4. I also had issues restarting the Server service on my Windows 7 machine, sometimes it would fail to restart or report that one service could not be stopped (I didn't record the exact error message). If you get this just restart the system and it will easily take care of the issue.
5. You may also want to make your Master Browser system the 'preferred' MB on your network to do this go in the Registry to HKLM\CurrentControlSet\Services\Browser\Parameters, open the MaintainServerList string and change the value data to Yes. Then create a new string named 'IsDomainMaster' open it and enter Yes for value data. This will not force the system to always be the the MB, but will make it much more likely if any other windows machines connect to your network in the future.
6. If you have a WINS server it makes life 100 times easier, just set the WINS server addy on your network preferences on your mac, or have it pushed down through DHCP and life is good, your computers will display in Finders Network pane. But who wants to have a WinNT/2000/2003 server running in their house?

As I said before, there is probably a better way to get this working but I have not found it yet. For now I am satisfied as it is, but I may try doing more searching on this just out of curiosity. I also hope that Apple and/or Microsoft will resolve this issue as this is a very annoying pain point for users and it doesn't help anyone by not having it work, it shouldn't take all the above steps just to be able to click on my Windows machines from a list on OSX and access shares. I know the typical answer from both companies would be "well it is because the other company does not support this or that feature", if thats the case, fix it. Ok, not trying to rant to much, I do hope that some of the developers of either product actually read this and see this as a necessary thing to resolve.

I hope that this helps someone out there looking to resolve this issue as well.
Greg

see my last reply for the 'work around' solution.

No, once I setup my Win7 machine to be the master browser I have not had any issues with any of my macs seeing my windows machines. Maybe there is another machine on your network that is also a master browser? When the machines disappear open up a terminal on your mac and do the command

nmblookup -m -- -,

With punctuation marks and all, is the master browser a different machine then the one you are trying to use?

Hope this helps,
Greg

The other thing you might be able to try is using wireshark, although I had issues running it on the latest update of Leopard as well as issues running it on Win7, but if you have Vista it will work fine. You can try monitoring for update packets in the LANMAN protocol, you should see one every so often addressed to your Mac whose contents includes the list of machines on your network. You can also take a look at the Browser, NBNS and NBSS traffic to see if there is anything going on that looks fishy.

Greg