Unable to map drives/home LAN

antares · 13 Mar 2014

Hi, I have a home wired LAN with the following configuration:
1) A Win 7x64 PC (static IP)
2) A Win 8.1x64 LAPTOP (static IP)
3) A Synology NAS (static IP)
3) A TP-LINK TL-R600VPN Wired Router connected to a cablemodem (internet access WAN) and to the switch.
4) A Trendnet 8 port switch connected to the 3 clients (PC, Laptop and NAS) and to the router (TP-LINK)

I have created a Windows Homegroup (Home/Private) from either the PC or Laptop going step by step as per these instructions and making sure that in both the PC and Laptop all requirements are met (required services, adapter settings, etc). The Homegroup is created successfully but the following issue arises:

- From the PC I can access shared files in the Laptop (by going to Windows Explorer/Network for example). From the PC I can also access the NAS shared files.
- From the Laptop, even though the Homegroup shows "Joined", I cannot access any shared file in the PC or NAS (it will show Error 53, network path not found). If I try to map a network drive (to directly access a shared folder in either the PC or NAS), it will also display an error saying that the network path cannot be found. However from the laptop I can access the NAS using the browser (Firefox, IE, etc).

So what is preventing the access to shared folders in the LAN from the laptop?

Thanks for any clue.

Kari · 13 Mar 2014

Try disabling your firewall, your error code is known to be caused by a firewall. If it works firewall disabled, you have to make new rules for firewall when enabling it again.

antares · 14 Mar 2014

Thanks Kari, I was ready to give up and reinstall Win8, but then I remembered that once I had my firewall (NIS2014) block NetBIOS. So I went to the firewall settings and unblocked NetBIOS and voila, now my laptop can access shared folders in my PC and my NAS, and was able to map the NAS and folders from the PC using Windows Explorer.Now the question remains, why blocking NetBIOS in the firewall causes this behavior?

Kari · 14 Mar 2014

antares said:

Now the question remains, why blocking NetBIOS in the firewall causes this behavior?

Homegroup and sharing between your Windows 7 computers does not need NetBIOS over TCP/IP. From Wikipedia:

NetBIOS over TCP/IP (NBT, or sometimes NetBT) is a networking protocol that allows legacy computer applications relying on the NetBIOS API to be used on modern TCP/IP networks.

In your case, I believe that as NetBIOS is enabled although not necessary and firewall blocked it, that was the reason. You might want to test this, block the NetBIOS again in your firewall, then disable NetBIOS on both Windows 8 laptop and Windows 7 desktop, reboot and see if sharing works.

Out of personal interest I just disabled NetBIOS on 4 Windows 7 and 8 computers, Homegroup and sharing worked flawlessly.

Kari

antares · 14 Mar 2014

Kari, I have my firewall's "Automatic Program Control" disabled, meaning that I'm prompted to block or allow access each time a program needs it. At the time I manually set Netbios to be blocked because for some reason the Shieldsup test with Netbios enabled made my laptop not stealth. As said, allowing Netbios in the firewall's Program rules solved my homegroup/sharing issue. I just blocked it again for testing purposes and the issue comes back again, i.e. the laptop is unable to access/map shared folders in other LAN clients (PC, NAS). Unblocking Netbios solves this again. So yes, Netbios was the issue. But then as you say "Homegroup and sharing between your Windows 7 computers does not need NetBIOS over TCP/IP", which makes this case more interesting.

Kari · 14 Mar 2014

NetBIOS is a remain from pre-Vista era. It was / is needed to allow some legacy apps to connect to a TCP/IP network. As such, it is absolutely not needed in Windows 7 / 8 / 8.1 networks and homegroups.

A simple test which you can do easily and fast is to disable NetBIOS on both your Windows 8.1 laptop's NIC properties, and do the same on your Windows 7 desktop's NIC. You'll find out that both Homegroup and normal network shares work as before.

antares · 14 Mar 2014

Kari said:

A simple test which you can do easily and fast is to disable NetBIOS on both your Windows 8.1 laptop's NIC properties, and do the same on your Windows 7 desktop's NIC. You'll find out that both Homegroup and normal network shares work as before.

I just checked my Windows 7 PC's NIC properties and there is no Netbios component listed. I'll check my Win 8 laptop's NIC later and report back.
UPDATE: I just checked my Win8 laptop, there's no Netbios component listed in the NIC's properties.

Kari · 14 Mar 2014

You sure? Check this:

Unable to map drives/home LAN-2014-03-14_16h46_13.png

antares · 14 Mar 2014

Hi Kari, sorry, my bad, I was looking wrong then. My Win7 PC has the NetBIOS set to Default. I'll check my Win8 laptop later and update this post.

antares · 14 Mar 2014

Kari said:

NetBIOS is a remain from pre-Vista era. It was / is needed to allow some legacy apps to connect to a TCP/IP network. As such, it is absolutely not needed in Windows 7 / 8 / 8.1 networks and homegroups.

A simple test which you can do easily and fast is to disable NetBIOS on both your Windows 8.1 laptop's NIC properties, and do the same on your Windows 7 desktop's NIC. You'll find out that both Homegroup and normal network shares work as before.

Hi Kari, I just checked and you're right, disabling NetBIOS as per your instructions does not affect the laptop's being able to access shared folders in the PC. However it does affect NAS shared folder accesibility. According to Synology's FAQ, the CIFS connection uses NetBIOS:
What network ports are used by Synology services? - Synology - Network Attached Storage (NAS)

Also, I checked again, and blocking NetBIOS with the Firewall also cripples the laptop's access to shared folders in the PC.