Windows UNC / File Sharing / Browsing (Can Ping, RDP but no UNC)

Hey guys,

I have a bit of a strange quirk here. I have a few different subnets (each a different office) in my network and I am coming across an issue where I cannot browse network shares on a few servers from 3 of my 6 subnets. I can ping, tracert, rdp into the server in question.

Here's a gist of what I've looked into so far with no avail.

- Checked Network Sharing settings and profiles.
- Checked DNS settings (WINS is not configured)
- Checked hosts files
- Checked Advanced Binding settings on the NIC
- Checked OS level Firewall (currently off)
- Checked specific services (such as Computer Browser)
- Re-IP'd the server in question
- Verified that Windows Updates have been applied
- Checked Local Security Policies revolving around File Sharing, Auditing etc.
- Checked the hardware firewall for any port blocks or restrictions.

Im sure I am missing a few other bullets. Also, a little more about the environment. The server in question is on a Windows Server 2012 R2 on a Citrix XenServer 6.1 platform (I know its outdated). But I have another server in the same XenServer Pool with no issues.

I bet it's something so simple that I may have overlooked but I am dropping this post here to see if any of you guys can lend your opinions and help me out or trigger a spark on my end to getting me back on track.

If you feel its networking (Cisco ASA/Router) related, could you provide details as to where to check and configure the setting on the running configuration so that I can relay it to my network engineer? If you feel its Win OS related, please share as well.

Thanks fellas!
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FOXActive Directory/Exchange EngineerCommented:
Is the server in question running Mcafee?
Bryant SchaperCommented:
Also does it work via ip, what we are trying to see is if SMB is working
zenki_fcAuthor Commented:
Hey guys! Thanks for the reply.

Unfortunately via IP, FQDN or server name. It will not establish a connection to view the shares available. I can ping or do just about anything else to it just not UNC or map drives for that matter.

The server is a fresh build, has no AV and Windows OS firewall is completely off.
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FOXActive Directory/Exchange EngineerCommented:
On the server in question do you have network discovery turned on?

ref link:
zenki_fcAuthor Commented:
Correct. It is enabled.

3 of the 6 main subnets and offices can browse to the shares on the server in question error free.

I keep leaning towards networking or routing issues. Any thoughts on how to test or view or troubleshoot connectivity between two addresses via Cisco appliances ? I don't think this is a Windows configuration error.
Bryant SchaperCommented:
Can you run an nmap and see if it can communicate from the other subjects and do a comparison?
FOXActive Directory/Exchange EngineerCommented:
The server(s) in question, are they physical or virtual servers?
zenki_fcAuthor Commented:
The server is a Virtual Server, running on XenServer 6.1
FOXActive Directory/Exchange EngineerCommented:
The nic on the vm , are you using vmxnet3?
zenki_fcAuthor Commented:
Foxluv, that's a negative. It's using a Realtek driver. Not the VMXNet3 drivers.

Bryant, I am not familiar with the nmap utility. Could you elaborate a bit more on what command I should run and what I am looking for?
FOXActive Directory/Exchange EngineerCommented:
Use the vmxnet3 drivers and test.   I assume you have already installed the vmtools as well on that server, if not install those as well.
Bryant SchaperCommented:
you will have to download, maybe get the zenmap gui, port scanning tool

we are looking for 137 138 139 and maybe 445


nmap -p 1-65535 -T4 -A -v serverip

Open in new window

zenki_fcAuthor Commented:
Foxluv, thanks for the input. I am only familiar on using that driver on ESXi. I'll loop back into that as a last resort.

Bryant, I downloaded the utility and your command crashes the program. However, I ran a similar command "intense" scan and the results are as follows.

135/tcp   unknown msrpc
139/tcp   unknown netbios-ssn
445/tcp   unknown microsoft-ds

Open in new window

Ports 137 and 138 do not show up on the server in question. Neither did they show up on servers that are healthy and error free.

Bryant SchaperCommented:
that would fine, 445 will be the important one, so it is open.  And you confirmed they can ping/dns resolve the server?  Are firewalls running on any of them?  If so can you shut them down just to confirm
zenki_fcAuthor Commented:
Bryant, yes. Firewall is fully disabled.

Im afraid I am still unable to connect. Going to look into enabling WINS but i dont think that will help much.
zenki_fcAuthor Commented:
I've figured out my issue. By Disabling SMB 2 or modifying my Riverbed appliance for SMB 2 corrected my issues.

Thank you.

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Bryant SchaperCommented:
so the firewalls were not disabled, where did the riverbed come from?  Happy you found the solution as it should have been working after everything we checked.
zenki_fcAuthor Commented:
Bryant, I was led to believe by the Network Engineer before he left on vacation that the Riverbed appliance had been configured to work with all versions of SMB. Unfortunately, due to bad information it took me along for a ride of useless troubleshooting. Skipping the SMB protocols, for that I apologize.

However, Thank you for being helpful. I did learn new tools to work with (Nmap). At least something useful came out of this post.
Bryant SchaperCommented:
happy to hear, glad we could assist
zenki_fcAuthor Commented:
Continued troubleshooting steps and measures led me to SMB protocols being the issue.
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Windows Server 2012

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