Going insane - "The specified network name is no longer available"

[Sonicmojo]

All,

A few weeks back I updated my ASUS RT-66U to Merlin Fork 374.43 33e7j9527 and all seemed to be fine. There are 8 physical machines on my network and a few VMs that I use for testing OS builds. This is a workgroup setting and ALL machines are part of a workgroup - simply called WORKGROUP.

On one of my servers I run ManageEngine's Desktop Central v10 management software. It has been running superb for over a year - but sometime after this router upgrade - something has happening with this server - either it's DNS entries or something it is getting from the router.

Within DesktopCentral - when I ask it to look for machines on the "WORKGROUP" - it has suddenly started coming back with this error (See screencap).

Tech support for DesktopCentral is telling me there is a DNS issue somewhere OR the DNS suffix is wrong in my setup. Problem with that is that I have never used a DNS suffix so I am stumped.

I have redone the network settings on the server about 10 times. I have assigned a static address and allowed the ASUS to serve up an address via DHCP. I have cleared all the caches I can think of. The next target is the router itself. Why would the router (if it's the problem) suddenly forget the network name of "WORKGROUP".

If anyone has seen this message in their travels and can tell me where I need to be looking - I would be forever grateful

Cheers,

Sonic.

 

[agilani]

All,

A few weeks back I updated my ASUS RT-66U to Merlin Fork 374.43 33e7j9527 and all seemed to be fine. There are 8 physical machines on my network and a few VMs that I use for testing OS builds. This is a workgroup setting and ALL machines are part of a workgroup - simply called WORKGROUP.

On one of my servers I run ManageEngine's Desktop Central v10 management software. It has been running superb for over a year - but sometime after this router upgrade - something has happening with this server - either it's DNS entries or something it is getting from the router.

Within DesktopCentral - when I ask it to look for machines on the "WORKGROUP" - it has suddenly started coming back with this error (See screencap).

Tech support for DesktopCentral is telling me there is a DNS issue somewhere OR the DNS suffix is wrong in my setup. Problem with that is that I have never used a DNS suffix so I am stumped.

I have redone the network settings on the server about 10 times. I have assigned a static address and allowed the ASUS to serve up an address via DHCP. I have cleared all the caches I can think of. The next target is the router itself. Why would the router (if it's the problem) suddenly forget the network name of "WORKGROUP".

If anyone has seen this message in their travels and can tell me where I need to be looking - I would be forever grateful

Cheers,

Sonic.

"workgroup" settings are typically part of windows operating systems and typically use broadcast messages i believe as part of smbv1 protocol which got deprecated/disabled on version 1709 and after. Is this part of our problem?

https://support.microsoft.com/en-us/help/4034314/smbv1-is-not-installed-by-default-in-windows

 

[MichaelCG]

Outside of DNS/DHCP, the router has no function in this activity. If you are dependent upon "browsing" the network, that is a broadcast function which has nothing to do with the router. I 2nd the previous response that there is a good chance this is related to changes made by MS regarding some of the older versions of SMB and what functions have been removed.

 

[Sonicmojo]

Thanks guys

This is an interesting angle - however - I am well aware of the SMB1 changes as of Win 10 1709 (which is on all my clients). I also disabled SMB1 on all my 2012R2 servers months ago (via Powershell) and had no issues adding computers within Desktop Central - that is up until about 10 days ago or so.

I DID make some DNS changes on the router a few weeks back during a firmware update - which I have since reversed...so this is a very odd scenario.

Here is what ManageEngine desktop support is saying about the error:

" We have confirmed that the error message shown as a result of the Desktop Central being unable to access the network resources of this workgroup.

1. Kindly check the DNS for any changes that might have been recently made and verify if the DNS suffix provided for the workgroup in DC is valid.
2. Try disabling anti-virus programs, if any, that might block Desktop Central from accessing shared resources.


The server is trying to fetch details on the workgroup from DNS - But since it cannot do that - It displays this message"

Clearly they are focused on DNS - which logically points to networking or the router or something DNS related. I am at loss as to what I am missing.

I can easily re-enable SMB1 on the server to see if that makes a difference but it's not something I want to leave enabled given the current attack vector this protocol allows. And I cannot believe that ManageEngine would allow SMB1 to be a basis for correct operation here in 2018.

Will keep trying things and see if anything good comes of it.

Sonic.

 

[ColinTaylor]

"The specified network name is no longer available". It is not apparent from the screen shot what "network name" it is looking for. It sounds like it's looking for something like \\RT-AC66U. Is there some way of finding out what ManageEngine is looking for, maybe a config file you can look at?

Have you changed the routers Device Name (i.e. RT-AC66U)?

BTW is your "RT-66U" an RT-N66U or an RT-AC66U?

 

[Sonicmojo]

"The specified network name is no longer available". It is not apparent from the screen shot what "network name" it is looking for. It sounds like it's looking for something like \\RT-AC66U. Is there some way of finding out what ManageEngine is looking for, maybe a config file you can look at?

Desktop Central is looking for the workgroup with the name WORKGROUP so it can poll the machines and see which ones have an agent install and which do not.

I should see a listing here of about 12 machines hanging off the tree. What I get is this error now

BTW is your "RT-66U" an RT-N66U or an RT-AC66U?

Sorry - my router is the RT-AC66U. Missed a few letters there.

The more I investigate - the more I think is has something to do with SMB1 etc.

Sonic.

 

[ColinTaylor]

It seems a bit odd they're saying it's trying to get "details on the workgroup from DNS" whereas they're really two different things.

If you've turned off SMBv1 on your clients and the router as you say then there won't be anything to browse in the workgroup because that's a function of SMBv1.

Is suppose the quickest way to test would be to re-enable SMBv1 on the router or one of the PC's and try again.

 

[john9527]

Are you using the router as the Master Browser or WINS server? Do you have a USB disk on the router?

There was a recent change made in Merlin that I picked up in my fork, such that
if you have a USB disk attached, you must have sharing enabled for MB/WINS to be active (this was to prevent unintentional sharing, since MB/WINS enabled samba sharing even if you had it disabled).

 

[Sonicmojo]

Would love to use the router as master browser but have no idea on how to make that work. I do not have a USB disk attached but see that "Force as master browser" is on. Clearly that is not working since I see another machine on the network acting as master browser right now

Anything that you can do to explain how to get that working would be great. I am not using WINS at all.

Sonic.

 

[Sonicmojo]

If you've turned off SMBv1 on your clients and the router as you say then there won't be anything to browse in the workgroup because that's a function of SMBv1.

How/where would I check for SMB1 on the router?

Is suppose the quickest way to test would be to re-enable SMBv1 on the router or one of the PC's and try again.

I re-enabled it on the server - did not make a bit of difference.

Sonic.

 

[agilani]

It seems a bit odd they're saying it's trying to get "details on the workgroup from DNS" whereas they're really two different things.

If you've turned off SMBv1 on your clients and the router as you say then there won't be anything to browse in the workgroup because that's a function of SMBv1.

Is suppose the quickest way to test would be to re-enable SMBv1 on the router or one of the PC's and try again.

They have it confused with active directory which does use ms dns servers for similar functions. Workgroup functionality does not rely on dns like active directory.

 

[ColinTaylor]

How/where would I check for SMB1 on the router?

USB application > Servers Center > USB Application - Network Place(Samba) Share / Cloud Disk > Samba protocol version

 

[Sonicmojo]

USB application > Servers Center > USB Application - Network Place(Samba) Share / Cloud Disk > Samba protocol version

Does this even matter if the Samba share is not even turned on? Mine is not.

The way this panel reads - it looks as tho all of these controls only matter when the Share is active (and a USB stick is present). In my case I have no share and no USB plugged in.

?

Sonic

 

[ColinTaylor]

Does this even matter if the Samba share is not even turned on? Mine is not.

The way this panel reads - it looks as tho all of these controls only matter when the Share is active (and a USB stick is present). In my case I have no share and no USB plugged in.

I'm not sure, I've never used it without a USB stick in it. Try it. You can still enable the "share" even though there's no USB plugged in.

But it's probably academic. If you've verified that there's an SMB master browser on a Windows machine that should be enough. Doing a "net view" should confirm it.

 

[john9527]

Does this even matter if the Samba share is not even turned on? Mine is not.

The way this panel reads - it looks as tho all of these controls only matter when the Share is active (and a USB stick is present). In my case I have no share and no USB plugged in.

?

Sonic

Just for a test.....
set protocol to SMBv1 + SMBv2
Set Master Browser and WINS server to Yes
Press Apply
Change Enable Share to On

 

[Sonicmojo]

If you've verified that there's an SMB master browser on a Windows machine that should be enough. Doing a "net view" should confirm it.

That's another thing that simply does not work. If I type net view at a command prompt from my Windows 10 workstation or any other - I get:

System error 64 has occurred.

The specified network name is no longer available.

Which - ironically is the same error message coming from Desktop Central (the one that started this thread)

Sonic.

 

[Sonicmojo]

Just for a test.....
set protocol to SMBv1 + SMBv2
Set Master Browser and WINS server to Yes
Press Apply
Change Enable Share to On

John,

Holy crap! Desktop Central is working again - my computers are back! (See WorkgroupBack)

AND Net view suddenly works again too (See NetViewBack)

WTF is going on? Why would this obscure area of the router have such a major impact on the WORKGROUP? Is it because the router is now Master Browser? Or because SMB1 is active again?

I vaguely remember coming in here a while ago - but cannot remember if I turned the share on or off or what. Wow. I must have had the router as master browser previously.

This begs the next another question - if I shut all this down (or did not have this Samba share ability at all) - this would mean Desktop Central will suddenly forget what WORKGROUP is. AND netview will stop working etc? What's a guy to do if I get a new router someday?

Sonic.

 

[Sonicmojo]

And the RT-AC66U is now the master! after this debacle - I am never changing these settings again!

Sonic

 

[agilani]

Expect to have issues though. Making the asus router the master browser may be working, but the root problem is that your software is most likely expecting smbv1. If it only uses smbv1, then it may be getting the master browser from router, but it may have difficulty communicating directly with the machines in question. You should ask them what their plan is to support smbv2/smbv3.

 

[john9527]

Hypothesis on what happened....
- On the older router firmware, enabling Master Browser with SMBv1 would always be active regardless of the Enable sharing setting (you would still be sharing with it sharing off without knowing it, hence the change), You probably had Master Browser set.
- Windows removed SMBv1 support (especially SMBv1 server), leaving the router as the only client that really could perform as MB. I also seem to remember reading somewhere that MS went event further, and now will completely remove (not only disable) SMBv1 support if you don't have it active for a certain number of days (30?).
- When you upgraded the router firmware, you had MB set, but not sharing, which meant MB was not really active, and you lost the only available SMBv1 server.

@agilani makes a good point about inquiring about their plans for network discovery without SMBv1.