Vigor router not passing netbios request

1

A client has decided to change ISP. The new provider has supplied a Vigor 2830 which I am failing to configure correctly to replace the existing router (Thomson 585).

A Dell 2800 running Ubuntu 14 is a Xen dom0 which hosts amongst others things an Ubuntu 10 running a Samba file server. The domU has been configured to use the new local gateway and nameserver, namely the Vigor router.

With the new router LAN, DHCP, local DNS all seem fine however the samba server does not respond to the netbiosname. From WinXP and Win7 clients I can ping the IP and navigate to \\1xx.1xx.xx.14 but ping SMBSERVER or navigate to \\SMBSERVER times out with no response. Running 'nslookup' on the client I am getting the correct local nameserver and the correct response

nslookup SMBSERVER
Server:  1xx.1xx.1x.6
Address: 1xx.1xx.1x.6#53

Name:    SMBSERVER
Address: 1xx.1xx.xx.14

With the old router everything connects.

Curiously, when following this guide: http://www.draytek.com/index.php?option=com_k2&view=item&id=5242&Itemid=293&lang=en and I set the domain name of the samba server to SBMSERVER.COM the clients can connect.

I do not wish to rename the samba server as the client base is familiar with the existing name, document references and shortcuts are well established.

What are the chances the Vigor firmware has a bug where single word hostnames fail?

Eoin

Posted 2014-12-22T11:27:39.080

Reputation: 11

Where is the DNS running? – marsh-wiggle – 2014-12-22T11:48:12.480

DNS is on the Vigor. I can set a fixed name - IP easily, but the nameserver seems not to like single names (FQDN only?...) – Eoin – 2014-12-22T12:06:53.667

Can you enter a domain name in the Vigor? What is the primary domain suffix of the W7 workstation? If they are same, it will work without FQND. For W7 you find help here

– marsh-wiggle – 2014-12-22T12:20:02.320

Answers

1

I just realised that my DrayTek Vigor2920n router has a default rule that blocks NetBios, check to see if yours is the same. It's been causing all sorts of confusion!

In my web interface, I can check in Firewall > Filter Setup > Default Data Filter and see the first rule named "xNetBios -> DNS".

It seems there's a good reason for this security-wise - if an attacker from outside your network can connect to one of your systems on port 139 they can get all kinds of info about your internal network systems. More info here: http://www.techrepublic.com/blog/it-security/the-problem-with-netbios/

Jon.Mozley

Posted 2014-12-22T11:27:39.080

Reputation: 86