VPN: Troubleshooting Printing over VPN issues

Some Microsoft networking environments rely heavily on NetBIOS broadcasts to advertise and locate network resources (servers, print devices, etc). On a local LAN segment, this works fine, as broadcasts are propagated to every node on the local segment. When the network segments are separated, this mechanism fails, since firewalls generally are not configured to forward broadcasts to remote segments. And users are accustomed to finding these resources by clicking on the Network Neighborhood or My Network Places desktop icons, or by a mapped drive to the resources.

By default, SonicWall devices are configured to not pass Microsoft NetBIOS broadcasts across interfaces. Below, we will detail how to configure the SonicWall to pass these broadcasts over the VPN.

NOTE: In larger environments, these additional broadcasts may lead to a substantial increase in traffic, and this may not be recommended. Instead, it is recommended that the Microsoft networking environment be correctly configured using Active Directory and/or WINS services, which are components of Microsoft’s Windows 2003 Server.

NOTE:Correct use of AD and/or WINS will minimize issues when attempting to access Microsoft network resources across interfaces. Please refer to http://support.microsoft.com/default.aspx?scid=kb;en-us;160177 for a more detailed discussion of this topic.

The following checklist may help resolve printing over VPN issues:

1. Ensure that the printer has been configured and the local computers are able to print on the printer.
2. Ensure that the VPN connection is established.
3. Test the VPN tunnel to insure you are able to access other network resources behind the remote LAN.
4. Enable NetBIOS on the VPN policies.

CAUTION: :In SonicOS Standard, Uncheck Disable all VPN Windows Networking (NetBIOS) Broadcasts under the VPN |Advanced page before proceeding to the next step.

• In the VPN | Base Settings page click the edit icon under Configure for the VPN policy name you want to edit. The VPN Policy window is displayed.
• Click on the Advanced tab.
• Check the option Enable Windows Networking (NetBIOS) broadcast.
• Click OK.

NOTE:In SonicOS Enhanced, VPN Policies will auto-create IP Helper NetBIOS relay policies if the Enable Windows Networking (NetBIOS Broadcast checkbox is selected on the Advanced tab of the VPN Policy.

Resolution for SonicOS 6.2 and Below

The below resolution is for customers using SonicOS 6.2 and earlier firmware. For firewalls that are generation 6 and newer we suggest to upgrade to the latest general release of SonicOS 6.5 firmware.

NOTE:Correct use of AD and/or WINS will minimize issues when attempting to access Microsoft network resources across interfaces. Please refer to http://support.microsoft.com/default.aspx?scid=kb;en-us;160177 for a more detailed discussion of this topic.

The following checklist may help resolve printing over VPN issues:

1. Ensure that the printer has been configured and the local computers are able to print on the printer.
2. Ensure that the VPN connection is established.
3. Test the VPN tunnel to insure you are able to access other network resources behind the remote LAN.
4. Enable NetBIOS on the VPN policies.

CAUTION:In SonicOS Standard, Uncheck Disable all VPN Windows Networking (NetBIOS) Broadcasts under the VPN |Advanced page before proceeding to the next step.

• In the VPN |Settings page click the edit icon under Configure for the VPN policy name you want to edit. The VPN Policy window is displayed.
• Click Advanced tab.
• Check the option Enable Windows Networking (NetBIOS) broadcast.
• Click OK.

NOTE:In SonicOS Enhanced, VPN Policies will auto-create IP Helper NetBIOS relay policies if the Enable Windows Networking (NetBIOS Broadcast checkbox is selected on the Advanced tab of the VPN Policy.