TCP/IP NetBIOS Helper, WINS Tab, Netbt.sys

Hi all,

I am trying to work out exactly what each of these items do in terms of
networking?!

I have discovered that if I disable the netbios entries under the wins tab
of my network card, my computer stops listening on UDP 137, 138 and TCP
139... so I assume the effect of this, it that my machine is technically
unavailable for wins elections, and SMB over 139 (legacy clients)??

The TCP/IP NetBIOS helper seems to be an odd one, because the moment I
disable it, I cannot use UNC shares etc nor join a domain using a FQDN - why
is this exactly?? Do these things I am trying to do rely on NetBIOS in some
way, or is that without this service running, the requests do not get passed
down to the DNS resolver??!

Also what role does NetBT.sys perform in all of this... the reason I saw
this was because I discovered that the only way of shutting off port 445 on
my machine completely is to disable this??

Any advice on what these do technically and how they all affect each other
would be most appreciated!

Herb
Thu May 08 17:53:20 PDT 2008


"UselessUser" <UselessUser@discussions.microsoft.com> wrote in message
news:52B40916-628D-4DC8-ADDD-8AD9815539F5@microsoft.com...
> Hi all,
>
> I am trying to work out exactly what each of these items do in terms of
> networking?!
>
> I have discovered that if I disable the netbios entries under the wins tab
> of my network card, my computer stops listening on UDP 137, 138 and TCP
> 139... so I assume the effect of this, it that my machine is technically
> unavailable for wins elections, and SMB over 139 (legacy clients)??

Partly Right. WINS is a NETBIOS service (although there are no "WINS
elections").

SMB will still work -- that is a FILE TRANSFER (and more) protocol, but
it's use of NetBIOS name will fail since you have disabled NetBIOS.

Browsing will also stop working since it is a NetBIOS legacy service.

> The TCP/IP NetBIOS helper seems to be an odd one, because the moment I
> disable it, I cannot use UNC shares etc nor join a domain using a FQDN -
> why

Actually you CAN do these if you DNS works.

You can use UNC names with either DNS or IP addresses, but not the
NetBIOS names.

> is this exactly?? Do these things I am trying to do rely on NetBIOS in
> some
> way, or is that without this service running, the requests do not get
> passed
> down to the DNS resolver??!

(Modern) NetBIOS is a NAME resolution and API protocol.

UNC names will work just fine with DNS names on NT 4.0 and later.


Turn your NetBIOS back on -- you will be happier.

If you have more than one Subnet, then install WINS Server(s) and make
EVERY COMPUTER a "WINS Client" including (especially) the DCs
and other server class machines.

UselessUser
Fri May 09 01:24:02 PDT 2008

I am sorry to disagree, but without the TCP/IP NetBIOS helper service
running, with a working DNS implementation, I cannot access a share via unc
path using a FQDN... (Network location cannot be reached?)

If I then disable the NetBios stuff on the WINS tab, I then cannot even use
netbios names to access the unc share either...

What is going on here?

"Herb Martin" wrote:

>
> "UselessUser" <UselessUser@discussions.microsoft.com> wrote in message
> news:52B40916-628D-4DC8-ADDD-8AD9815539F5@microsoft.com...
> > Hi all,
> >
> > I am trying to work out exactly what each of these items do in terms of
> > networking?!
> >
> > I have discovered that if I disable the netbios entries under the wins tab
> > of my network card, my computer stops listening on UDP 137, 138 and TCP
> > 139... so I assume the effect of this, it that my machine is technically
> > unavailable for wins elections, and SMB over 139 (legacy clients)??
>
> Partly Right. WINS is a NETBIOS service (although there are no "WINS
> elections").
>
> SMB will still work -- that is a FILE TRANSFER (and more) protocol, but
> it's use of NetBIOS name will fail since you have disabled NetBIOS.
>
> Browsing will also stop working since it is a NetBIOS legacy service.
>
> > The TCP/IP NetBIOS helper seems to be an odd one, because the moment I
> > disable it, I cannot use UNC shares etc nor join a domain using a FQDN -
> > why
>
> Actually you CAN do these if you DNS works.
>
> You can use UNC names with either DNS or IP addresses, but not the
> NetBIOS names.
>
> > is this exactly?? Do these things I am trying to do rely on NetBIOS in
> > some
> > way, or is that without this service running, the requests do not get
> > passed
> > down to the DNS resolver??!
>
> (Modern) NetBIOS is a NAME resolution and API protocol.
>
> UNC names will work just fine with DNS names on NT 4.0 and later.
>
>
> Turn your NetBIOS back on -- you will be happier.
>
> If you have more than one Subnet, then install WINS Server(s) and make
> EVERY COMPUTER a "WINS Client" including (especially) the DCs
> and other server class machines.
>
>
>

Herb
Fri May 09 08:08:09 PDT 2008


"UselessUser" <UselessUser@discussions.microsoft.com> wrote in message
news:151D190D-51FB-42A3-A81F-0EECD7020F7D@microsoft.com...
>I am sorry to disagree, but without the TCP/IP NetBIOS helper service
> running, with a working DNS implementation, I cannot access a share via
> unc
> path using a FQDN... (Network location cannot be reached?)
>
> If I then disable the NetBios stuff on the WINS tab, I then cannot even
> use
> netbios names to access the unc share either...
>
> What is going on here?

Turn it back on and things will work.

> "Herb Martin" wrote:
>
>>
>> "UselessUser" <UselessUser@discussions.microsoft.com> wrote in message
>> news:52B40916-628D-4DC8-ADDD-8AD9815539F5@microsoft.com...
>> > Hi all,
>> >
>> > I am trying to work out exactly what each of these items do in terms of
>> > networking?!
>> >
>> > I have discovered that if I disable the netbios entries under the wins
>> > tab
>> > of my network card, my computer stops listening on UDP 137, 138 and TCP
>> > 139... so I assume the effect of this, it that my machine is
>> > technically
>> > unavailable for wins elections, and SMB over 139 (legacy clients)??
>>
>> Partly Right. WINS is a NETBIOS service (although there are no "WINS
>> elections").
>>
>> SMB will still work -- that is a FILE TRANSFER (and more) protocol, but
>> it's use of NetBIOS name will fail since you have disabled NetBIOS.
>>
>> Browsing will also stop working since it is a NetBIOS legacy service.
>>
>> > The TCP/IP NetBIOS helper seems to be an odd one, because the moment I
>> > disable it, I cannot use UNC shares etc nor join a domain using a
>> > FQDN -
>> > why
>>
>> Actually you CAN do these if you DNS works.
>>
>> You can use UNC names with either DNS or IP addresses, but not the
>> NetBIOS names.
>>
>> > is this exactly?? Do these things I am trying to do rely on NetBIOS in
>> > some
>> > way, or is that without this service running, the requests do not get
>> > passed
>> > down to the DNS resolver??!
>>
>> (Modern) NetBIOS is a NAME resolution and API protocol.
>>
>> UNC names will work just fine with DNS names on NT 4.0 and later.
>>
>>
>> Turn your NetBIOS back on -- you will be happier.
>>
>> If you have more than one Subnet, then install WINS Server(s) and make
>> EVERY COMPUTER a "WINS Client" including (especially) the DCs
>> and other server class machines.
>>
>>
>>