NetBIOS over TCP/IP NBDD Stopping Internet Access?

  • Thread starter Thread starter Ben
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Ben

Hi,

Yesterday one of our engineers was messing with DHCP scope options, and
decided to enable NetBIOS over TCP/IP NBDD (option 46) for some reason. At
the time no one noticed any effect. However, this morning people who were in
the office yesterday, but who were out the office today, found that they
could not get internet access. It seems they can resolve IP addresses, but
not names. They can't ping yahoo.com, but can ping the ip address of
yahoo.com.
We're not too sure how to fix this problem. We've disabled the DHCP scope
option, but it doesn't seem to make any difference.
Internally, we can get net access, and we can ping yahoo.com. Some of the
external people, have been able to VPN in, and can then get net access,
however, once they disconnect the VPN again, the problem comes back.
Does anyone know how to fix this? Or why this scope option would cause such
problems?

Cheers

Ben
 
Hi,

Yesterday one of our engineers was messing with DHCP scope
options, and
decided to enable NetBIOS over TCP/IP NBDD (option 46) for
some reason. At
the time no one noticed any effect. However, this morning
people who were in
the office yesterday, but who were out the office today, found
that they
could not get internet access. It seems they can resolve IP
addresses, but
not names. They can't ping yahoo.com, but can ping the ip
address of
yahoo.com.
We're not too sure how to fix this problem. We've disabled the
DHCP scope
option, but it doesn't seem to make any difference.
Internally, we can get net access, and we can ping yahoo.com.
Some of the
external people, have been able to VPN in, and can then get
net access,
however, once they disconnect the VPN again, the problem comes
back.
Does anyone know how to fix this? Or why this scope option
would cause such
problems?

Cheers

Ben
Click to expand...

I suspect the DNS is broken (whcih would explain why name resolution
has stoped working), try reseting the DNS (settings and all).
 
Hi Sparda,

I've tried adding the DNS entries manually, then doing ipconfig /flushdns
then /registerdns, and also rebooting, but neither worked. My laptop has the
problem now also. I got home from work, and tried to connect to my home LAN,
and it won't open any web pages, or ping any sites. Only way I can get
external access is to VPN into the office, and work off that LAN.
My home LAN has a netgear router that acts as a DHCP server, issuing IPs &
DNS, the machine I'm working from now works pefectly, but my laptop next to
me, running through the same router, will just not resolve external names!

Ben

Sparda said:
I suspect the DNS is broken (whcih would explain why name resolution
has stoped working), try reseting the DNS (settings and all).

--
Posted using the http://www.windowsforumz.com interface, at author's request
Articles individually checked for conformance to usenet standards
Topic URL: http://www.windowsforumz.com/NetBIOS-TCP-IP-NBDD-Stopping-Internet-Access-ftopict435458.html
Visit Topic URL to contact author (reg. req'd). Report abuse:
Click to expand...
http://www.windowsforumz.com/eform.php?p=1465026
 
Hi Sparda,

I've tried adding the DNS entries manually, then doing
ipconfig /flushdns
then /registerdns, and also rebooting, but neither worked. My
laptop has the
problem now also. I got home from work, and tried to connect
to my home LAN,
and it won't open any web pages, or ping any sites. Only way I
can get
external access is to VPN into the office, and work off that
LAN.
My home LAN has a netgear router that acts as a DHCP server,
issuing IPs &
DNS, the machine I'm working from now works pefectly, but my
laptop next to
me, running through the same router, will just not resolve
external names!

Ben

message

abuse:
http://www.windowsforumz.com/eform.php?p=1465026
Click to expand...

In that case, I would say that what windows is doing is trying to use
NetBIOS to resolve domain names, which obviusly isnt going to work
(since netBIOS is for computer names, rather than domain names) but,
unfortunatly for you, i am clurently clueles as to why windows would
do this.
 
This now has me stumped! I have tried adding specific DNS servers, rather
than allowing DHCP to issue them. I've disabled NETBIOS over TCP, and
released/renewed IP then flushed/registered DNS. I've even gone as far as
using netsh to re-install TCP/IP. Nothing works. The only way I can get to a
web site, is to enter the IP & hostname is the hosts file, I can then browse
that site. However following any links off to another webserver then brings
back the same old page can not be displayed error. I've gone though the
"checking connectivity for windows xp" artical on MS support, but everything
appears to be fine.
I'm lost! What else can I try, beside re-installing 15 users laptops??

Ben
 
Hi,
We're not using ICS, everyone seems to be having the same problem, even
though some people are using ADSL modems connected via USB, and some are
ADSL connected to network routers. When everyone is in the office we're all
connecting though a firewall, and web access works. Eveyone's home
connections WERE working, until this 1 change, which has now been removed.
I'll have a look though, it might shed some light, or offer possible
solutions.
Thanks.
Ben
 
Ben said:
This now has me stumped! I have tried adding specific DNS
servers, rather than allowing DHCP to issue them. I've
disabled NETBIOS over TCP, and released/renewed IP then
flushed/registered DNS. I've even gone as far as using
netsh to re-install TCP/IP. Nothing works. The only way I
can get to a web site, is to enter the IP & hostname is
the hosts file, I can then browse that site. However
following any links off to another webserver then brings
back the same old page can not be displayed error. I've
gone though the "checking connectivity for windows xp"
artical on MS support, but everything appears to be fine.
I'm lost! What else can I try, beside re-installing 15
users laptops??
Click to expand...
Can you post the ipconfig /all from one of the afffected
machines?

Cheers,

Cliff
 
This now has me stumped! I have tried adding specific DNS
servers, rather
than allowing DHCP to issue them. I've disabled NETBIOS over
TCP, and
released/renewed IP then flushed/registered DNS. I've even
gone as far as
using netsh to re-install TCP/IP. Nothing works. The only way
I can get to a
web site, is to enter the IP & hostname is the hosts file, I
can then browse
that site. However following any links off to another
webserver then brings
back the same old page can not be displayed error. I've gone
though the
"checking connectivity for windows xp" artical on MS support,
but everything
appears to be fine.
I'm lost! What else can I try, beside re-installing 15 users
laptops??

Ben
Click to expand...

Although a bit extrem (not to mention very risky) you could try
disabling the WINS server, making sure the WINS server isn’t
specvified in the clients, and manualy specifie a DNS.
 
Sure, here we go

Windows IP Configuration

Host Name . . . . . . . . . . . . : hhc9t0j
Primary Dns Suffix . . . . . . . : domain.com
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : domain.com
domain.com

Ethernet adapter Local Area Connection:

Media State . . . . . . . . . . . : Media disconnected
Description . . . . . . . . . . . : Broadcom 440x 10/100 Integrated
Controller
Physical Address. . . . . . . . . : 00-0B-DB-9C-5B-1A

PPP adapter BTopenworld:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
Physical Address. . . . . . . . . : 00-53-45-00-00-00
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 86.136.148.234
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 86.136.148.234
NetBIOS over Tcpip. . . . . . . . : Disabled

PPP adapter domain VPN:

Connection-specific DNS Suffix . : domain.com
Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
Physical Address. . . . . . . . . : 00-53-45-00-00-00
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.0.29
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 192.168.0.29
 
First. Although I can't say for sure what the problem really is,...I do
think that it had nothing at all to do with the change to the DHCP Scope. I
think there is a totally different problem/cause that waht you are chasing
after. I believe the the tech that made the change just happen to be
unlucky enough to make that change at the same time that another problem
started and he is getting the blame when it may have nothing to do with him.
 
Ben said:
Ethernet adapter Local Area Connection:

Media State . . . . . . . . . . . : Media disconnected
Description . . . . . . . . . . . : Broadcom 440x 10/100 Integrated
Controller
Physical Address. . . . . . . . . : 00-0B-DB-9C-5B-1A
Click to expand...

Why does the main NIC say the cable is unpluged and it has no TCP/IP
Settings at all?

PPP adapter BTopenworld:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
Physical Address. . . . . . . . . : 00-53-45-00-00-00
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 86.136.148.234
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 86.136.148.234
NetBIOS over Tcpip. . . . . . . . : Disabled

PPP adapter domain VPN:

Connection-specific DNS Suffix . : domain.com
Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
Physical Address. . . . . . . . . : 00-53-45-00-00-00
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.0.29
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 192.168.0.29
Click to expand...

How can there be two PPP Adapters running when the Physical Nic has the
cable unplugged? I guess they will run if they are Statically Assigned with
their TCP/IP Specs. Anyway, You can only have one Default Gateway per
machine. If you have more than one you will get all kinds of stupid and
strange behavior.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp
-----------------------------------------------------
 
Ben said:
Sure, here we go

Windows IP Configuration

Host Name . . . . . . . . . . . . : hhc9t0j
Primary Dns Suffix . . . . . . . : domain.com
Node Type . . . . . . . . . . . . : Hybrid
IP Routing Enabled. . . . . . . . : No
WINS Proxy Enabled. . . . . . . . : No
DNS Suffix Search List. . . . . . : domain.com
domain.com

Ethernet adapter Local Area Connection:

Media State . . . . . . . . . . . : Media disconnected
Description . . . . . . . . . . . : Broadcom 440x 10/100 Integrated
Controller
Physical Address. . . . . . . . . : 00-0B-DB-9C-5B-1A

PPP adapter BTopenworld:

Connection-specific DNS Suffix . :
Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
Physical Address. . . . . . . . . : 00-53-45-00-00-00
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 86.136.148.234
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 86.136.148.234
NetBIOS over Tcpip. . . . . . . . : Disabled

PPP adapter domain VPN:

Connection-specific DNS Suffix . : domain.com
Description . . . . . . . . . . . : WAN (PPP/SLIP) Interface
Physical Address. . . . . . . . . : 00-53-45-00-00-00
Dhcp Enabled. . . . . . . . . . . : No
IP Address. . . . . . . . . . . . : 192.168.0.29
Subnet Mask . . . . . . . . . . . : 255.255.255.255
Default Gateway . . . . . . . . . : 192.168.0.29
Click to expand...
Like Philip says, the *ethernet* appears to be disconnected.
However, assuming that this was not the problem, (and that
you had disconnected for some reason) can you post the
ipconfig /all for one of the clients?

Cheers,

Cliff
 
Phillip said:
Why does the main NIC say the cable is unpluged and it has no TCP/IP
Settings at all?





How can there be two PPP Adapters running when the Physical Nic has the
cable unplugged? I guess they will run if they are Statically Assigned with
their TCP/IP Specs. Anyway, You can only have one Default Gateway per
machine. If you have more than one you will get all kinds of stupid and
strange behavior.
Click to expand...
The second one's a VPN connection. I'd guess that it runs
over his connection to BTOpenWorld. My guess is that he's
given us the gateway machine's ipconfig.

Cheers,

Cliff
 
Enkidu said:
Like Philip says, the *ethernet* appears to be disconnected. However,
assuming that this was not the problem, (and that you had disconnected for
some reason) can you post the ipconfig /all for one of the clients?

Cheers,

Cliff
Click to expand...

Hi Cliff,

This is the IPconfig of one of the clients. I believe this particular person
uses a USB modem, to connect to BT Openworld, then initiates the VPN
connection over that connection. The disconnected Broadcom 44x network card
is the users in built LAN card he uses when in the office, but not at home.

I think this may have something to do with DNS. I ran ethereal on my laptop,
and found that when I tried to PING yahoo.com it was trying to resolve that
against the company's internal DNS server, not my ISPs DNS servers. Even if
I change my connection and specify the DNS servers manually, rather than
letting it pick them up from my ADSL router. Obviously, as our internal DNS
server isn't accessible, it fails. This would also explain why net access
works when the user connects tot he VPN.

Ben
 
Phillip Windell said:
First. Although I can't say for sure what the problem really is,...I do
think that it had nothing at all to do with the change to the DHCP Scope.
I
think there is a totally different problem/cause that waht you are chasing
after. I believe the the tech that made the change just happen to be
unlucky enough to make that change at the same time that another problem
started and he is getting the blame when it may have nothing to do with
him.
Click to expand...

I'm beginning to think your right. After removing the scope option the error
still remains, and as I said in the post to Cliff below, the error seems to
be that when you try and resolve a host name, it's trying to contact our
internal DNS server, and not the user's ISP's DNS servers.

Ben
 
Phillip Windell said:
Why does the main NIC say the cable is unpluged and it has no TCP/IP
Settings at all?
Click to expand...
I believe this particular person uses a USB modem, to connect to BT
Openworld, then initiates the VPN connection over that connection. The
disconnected Broadcom 44x network card is the users in built LAN card he
uses when in the office, but not at home.
How can there be two PPP Adapters running when the Physical Nic has the
cable unplugged? I guess they will run if they are Statically Assigned
with
their TCP/IP Specs. Anyway, You can only have one Default Gateway per
machine. If you have more than one you will get all kinds of stupid and
strange behavior.
Click to expand...

I will have a look at the gateway issue, this IPConfig dump was taken while
the user was connected to the VPN. Would it be useful if I took a dump while
the user is disconnected from the VPN?
 
Ben said:
I will have a look at the gateway issue, this IPConfig dump was taken
while the user was connected to the VPN. Would it be useful if I took a
dump while the user is disconnected from the VPN?
Click to expand...
OK, I just read that last sentence, and realised I could probably have
worded it slightly better! :-)
 
Yay! I've fixed the problem. You were right. Nothing to do with that DHCP
scope entry. Someone put a group policy entry in (admin template >
networking > dns client) with the internal DNS server IP, which was over
writing the local DNS server entries!

Thanks for everyones help!

Ben
 
Ben said:
I'm beginning to think your right. After removing the scope option the error
still remains, and as I said in the post to Cliff below, the error seems to
be that when you try and resolve a host name, it's trying to contact our
internal DNS server, and not the user's ISP's DNS servers.
Click to expand...

That is what it is supposed to do. They should never query the ISP's DNS
directly. Only your AD/DNS should query the ISP's DNS, and do so only after
it couldnot resolve the request from its own database.

--
Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com
-----------------------------------------------------
Understanding the ISA 2004 Access Rule Processing
http://www.isaserver.org/articles/ISA2004_AccessRules.html

Microsoft Internet Security & Acceleration Server: Guidance
http://www.microsoft.com/isaserver/techinfo/Guidance/2004.asp
http://www.microsoft.com/isaserver/techinfo/Guidance/2000.asp

Microsoft Internet Security & Acceleration Server: Partners
http://www.microsoft.com/isaserver/partners/default.asp
-----------------------------------------------------
 
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