What would cause netbios to "apparently" stop working even though ping works?

This has me stumped.  I have two Netgear FVS318 VPN routers at two offices.  I have them configured to make a VPN connection both ways to connect the two networks via cable internet on either side.  Everything was working fine when suddenly it just stopped working.  I can ping either way and I can even remotely access either router configuration pages using their LAN IP addresses.  So at the network level everything is fine.  But I can no longer view network shares by windows NETBIOS names. (e.g. \\computername).

The connection dropped when I was trying to do a database syncronization process over the VPN connection.  That was the first time I've ever tried that and it was taking quite a long time.

What's even weirder is that I can browse some of the remote clients using \\"IP Address", but not all of them.

Netbios over IP is enabled on the VPN settings and I have not changed any settings since it was working before.

Any help is greatly appreciated.
sideout92Asked:
Who is Participating?
I wear a lot of hats...

"The solutions and answers provided on Experts Exchange have been extremely helpful to me over the last few years. I wear a lot of hats - Developer, Database Administrator, Help Desk, etc., so I know a lot of things but not a lot about one thing. Experts Exchange gives me answers from people who do know a lot about one thing, in a easy to use platform." -Todd S.

ChiefITCommented:
Your ISP may be refusing traffic on those ports. The default protocol to network shares and printers these days is SMB on port 445. Some ISPs are blocking these because of the violations and vulnerabilities to these shares.

http://ourworld.compuserve.com/homepages/timothydevans/browse.htm
0
ChiefITCommented:
Old school way
http://www.experts-exchange.com/OS/Microsoft_Operating_Systems/Server/Q_23652843.html

New school way is to get SMB shares going through the tunnel on port 445 and Netbios datagram port 137. Now some ISP's block port 445 due to the vulnerabilities of that data. Also, some routers are now encrypting port 445 to secure the shared traffic. So, this setup depends upon what is offered to you.
http://ourworld.compuserve.com/homepages/timothydevans/browse.htm
0

Experts Exchange Solution brought to you by

Your issues matter to us.

Facing a tech roadblock? Get the help and guidance you need from experienced professionals who care. Ask your question anytime, anywhere, with no hassle.

Start your 7-day free trial
sideout92Author Commented:
Thanks for the feedback.  I'll check if my ISP made any changes to that effect.
0
It's more than this solution.Get answers and train to solve all your tech problems - anytime, anywhere.Try it for free Edge Out The Competitionfor your dream job with proven skills and certifications.Get started today Stand Outas the employee with proven skills.Start learning today for free Move Your Career Forwardwith certification training in the latest technologies.Start your trial today
Internet Protocols

From novice to tech pro — start learning today.

Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.