Technology Woes

I have a lot of technology in the studio. I am always looking for ways to use technology effectively to solve audio engineering problems. One problem that I used to face was how to remote control Pro Tools. In the past I used to set up in the control room and try to manage guitar, console, transport control, monitors, keyboards and mice with varying degrees of success and frustration. All that changed when I discovered remote desktop.

I use a notebook computer on the wireless LAN that connects to the Pro Tools workstation through remote desktop. The notebook then becomes the Pro Tools workstation. The monitor and keyboard on the notebook controls Pro Tools remotely. This allows me to set up in one of the talent rooms and control my studio remotely via the notebook. Very cool. Except something happened. I tried to connect to my network and I received a “network not accessible” error. Thus began a prolonged and strange battle with technology.

My first step was to search Google to see if anyone else had this experience. Turns out that most of the world has run into it if they network more than one computer. I found a Microsoft article on the issue here. This knowledge base article precisely described the symptoms I was experiencing: I could not browse other computers in the workgroup, I could not access shared folders or files, I received the dreaded error message: “Workgroup Name is not accessible. You may not have permission to use this network resource”.

The cause was due to NetBIOS over TCP/IP not being turned on and the computer browser service not being started. The resolution is to turn on NetBIOS and to ensure the computer browser service is started. So I tried the resolution.

Didn’t work. Nada. Zip. Still got the same error message.

I crawled on the web for several hours last night and avoided some much needed sleep in the process. Dozens of suggested actions to resolve the problem were discovered and all of them failed. I don’t know why the notebook would no longer see my network. It worked fine for almost a year.

And then I found the answer.

Most networks provision an address for each machine on a network. This address, known as an IP address, is often provisioned through a DHCP service. Some networks operate as broadcast networks and some operate as point-to-point. If you happen to connect a notebook computer to a different network, one that uses point-to-point, then the DHCP service might make a small change in your computer’s registery file.

If a parameter is *optionally* set by *some* DHCP server then that parameter will persist in the registry regardless of any other actions you might try. The parameter is “DhcpNodeType”. Not all DHCP servers set this parameter. I obviously had the misfortune of connecting to another network, which I often do when I travel, where the DHCP service changed this parameter. My network’s DHCP server does not change the parameter and that is why the notebook failed to join the workgroup and gave the error message. This is because my network is set up using the default “broadcast” node type and the persisting DhcpNodeType parameter continued to tell the malfunctioning machine to be a “point-to-point” node. The two types do not talk to each other.

The Solution: check the registry for the DhcpNodeType parameter. If the value is 2 then change it to 1 and reboot. Optionally one may choose the value 4 or 8 to have a computer work in both environments.

Registry Location:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netbt\Parameters
Key: DhcpNodeType
Value Type: REG_DWORD – Number
Valid Range: 1,2,4,8 (B -node, P-node, M-node, H-node)
Default: 1 or 8 based on the WINS server configuration
Description: This optional parameter specifies the NBT node type. It is written by the DHCP client service, if enabled. This parameter determines what methods NetBT uses to register and resolve names. A B-node system uses broadcasts. A P -node system uses only point- to-point name queries to a name server (WINS). An M -node system broadcasts first, and then queries the name server. An H -node system queries the name server first, and then broadcasts. Resolution through LMHOSTS and/or DNS, if enabled, follows these methods. If this key is not present, the system defaults to B -node if there are no WINS servers configured for the network. The system defaults to H -node if there is at least one WINS server configured.

By the way, there is another optional parameter at the same registry location that one may add which will override any DHCP server value placed in the DhcpNodeType.

NodeType
Key: Netbt\Parameters
Value Type: REG_DWORD – Number
Valid Range: 1 – 8
Default: 1
Description: This parameter specifies the NBT node type. It is an optional parameter that, if present, will override the DhcpNodeType parameter.

I weep for Microsoft. What a sad journey to make to ensure that your computer connects easily to a peer-to-peer network. “Hey”, tech support asks, “Didja happen to check whether you are B-node or P-node?”

11 replies
  1. Robert Cragie
    Robert Cragie says:

    Thanks for this really useful info. This happened to me when I used a laptop on a hotel wireless network then found that when I took it home I could no longer see the home office server. I added the parameter on the home office server and changed it on the laptop so they were both 4 and bingo! it worked. Thanks again

    Reply
  2. Michael Torrey
    Michael Torrey says:

    Richard,

    Guess it’s been a while since you wrote this, and it seems that earlier this year someone else found it to work, I’m ready to try it myself but I can’t find the key at this location and I can’t figure out how to add either one of these keys. If you’re monitoring this I sure could use a bit of help.

    Your studio looks wonderful and I wish I could record there. Thanks!

    Reply
  3. Richard Cleaver
    Richard Cleaver says:

    Hello Michael,

    All comments are moderated so I do see them all, even if they refer to posts from several years back.

    Keep in mind that this was a very specific issue with Windows XP. To check the registry value, you would need to open up the file with regedit and travel down the tree:

    HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Netbt\Parameters

    And, in that section of the registry, there will be a value for DhcpNodeType.

    Not sure why that value would be absent in your registry. But I am a bit limited in being able to troubleshoot through a blog. You can always send me a PM at my contact address listed at the top of the blog.

    I no longer run XP in the studio. I switched over to Macs where I don’t worry about any of this nonsense 🙂

    Good luck and I hope you get your problem resolved!

    Reply
  4. Laurent Marjollet
    Laurent Marjollet says:

    Richard,

    Many thanks. This XP issue and resolution is by far clearer described here than at support.microsoft.com
    That is good news since I just faced the issue 🙂

    Thanks again.

    Reply
  5. Bob C
    Bob C says:

    Wow! This was a pain!
    I happened to use my work laptop at another companies office, logged onto a wireless connection there and returned back to the office. When i plugged into the network and tried to access files, i got the ole “you might not have permission to use this network”…blah blah blah. I could not access my office network files but did have internet access through the network.

    I think usimg the other wireless connection may have been the problem because i tried your fix and it worked. Many thanks. I will be passing this info on.

    Why would XP allow the change in the registry without alerting you or somehow logging that minute change?

    Oh well, thanks again!

    Bob

    Reply
  6. Gaspard Leon
    Gaspard Leon says:

    Well I just resolved this at home for my flatmate’s new Windows Vista (Ultimate edition) laptop, so this is not only limited to XP machines.

    I actually didn’t find this site (until after it was fixed,) but one similar, and was unimpressed that this CRITICAL setting has NO GUI to control it, you can uselessly flail about in the network settings on an XP or Vista machine for hours and not fix a damned thing…

    Shame on Microsoft for not making this important network setting discoverable easily.

    I have in the past seen people reinstall windows just because it would not connect to a network, now I finally know why…

    Personal note: although my flatmates use Windows, I use Ubuntu linux, which has it’s own share of oddities, but nothing as inane as this thankfully.

    Reply
  7. MJMentes
    MJMentes says:

    Great info. My node was set to hybrid…..what does that mean cause they still don’t work. my xp desktop can see my vista laptop but can’t access anything on it. My vista laptop can’t see my xp.

    Reply

Trackbacks & Pingbacks

  1. […] option that causes home networking to not work correctly!! anyway read what this guy has to say: http://www.richardcleaver.com/?p=15 the short of it is if the setting of your DHCP NodeType is set to 2 then your home (workgroup, no […]

  2. […] This would be a good time to deactivate IPv6 and enable network sharing and discovery too. Check your node type. […]

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