Master browser

Hi
How is master browser working in a W2K3 environment today?
Event viewer logs shows different servers are acting as master browser
and the network sniffer reports some broadcast war going on.
In early days I remember it was normal to fix master browser to the
PDC and deny clients to become a master browser (reg. hack). As far I
understand it's just a wins/netbios thing. Who should be preferred as
master browser? PDC Emulator?
What is best practice today?

Jordan

No, the PDC Emulator doesn't have to be the master browser in W2k3 . The
first domain controller to register the domain name (ie the <domainname
1b> special name) becomes the domain master browser.

The basic situation hasn't changed much since NT days. The master
browser is still elected. The major problem is still multihomed browse
masters.

Election broadcasts and workstations apparently trying to become master
browsers are usually a symptom of a fundamental browser failure. It happens
when a client can't find a master browser when it needs one. The most common
cause is that the master browser is multihomed and the client is looking at
the "wrong" IP address.

You can certainly disable the computer browser service on workstations
as long as you have enough servers to do the job. You can also disable the
computer browser service on multihomed or remote access servers (which
become multihomed when a client connects) if you have enough single homed
servers to do the job.

Troubleshooting the browser service is still basically the same as in
NT. See KB188001 for a description of the computer browser service and
KB188305 for a troubleshooter.

Jordan wrote:
> Hi
> How is master browser working in a W2K3 environment today?
> Event viewer logs shows different servers are acting as master browser
> and the network sniffer reports some broadcast war going on.
> In early days I remember it was normal to fix master browser to the
> PDC and deny clients to become a master browser (reg. hack). As far I
> understand it's just a wins/netbios thing. Who should be preferred as
> master browser? PDC Emulator?
> What is best practice today?
>
> Jordan

It helps to understand there are multiple masters, a domain master
browser (DMB), segment master browser (SMB) and a backup
master browser (BMB). The DMB or domain master browser is
always the PDC or PDC emulator for W2k and W2k3, this machine
will register the domain name 1b unique name which guarentees it will
be the DMB. The DMB is responsible for gathering the list from all
SMBs to merge for a domain wide list as well as querying WINS for
all domain name 1b names in order to obtain their lists. The PDC or
PDC emulator by default is the SMB for it's local endpoint.

The SMB is responsible for gathering the local list and passing back
to the DMB as well as making available the domain wide list for all
clients on it's endpoint. The SMB is elected through a browse
election process using OS criteria putting DCs higher up the list.

There is a registry value which will give a machine a better chance
of becoming the SMB, called IsDomainMaster, also an entry which
prevents the machine from becoming a master browser called
MaintainServerList. By default all machines including the DMB
will have an IsDomainMaster setting of false and a MaintainServerList
setting of Auto. When a machine cannot contact an SMB it will
force an election in order elect a new master browser. This would
suggest a communication issue between the SMB all the clients.

When such browse issues occurred in the NT 4.0 it was common
to turn off browsing on the clients by changing the MaintainServerList
value to False, this prevents the machine from becoming a master
browser.

Having said all that it could be a WINS issue or perhaps a multihomed
master browser as Bill suggested. It could be packet filtering via a
firewall or router preventing the DMB or SMBs being contacted..


<Jordan> wrote in message news:(E-Mail Removed)...
> Hi
> How is master browser working in a W2K3 environment today?
> Event viewer logs shows different servers are acting as master browser
> and the network sniffer reports some broadcast war going on.
> In early days I remember it was normal to fix master browser to the
> PDC and deny clients to become a master browser (reg. hack). As far I
> understand it's just a wins/netbios thing. Who should be preferred as
> master browser? PDC Emulator?
> What is best practice today?
>
> Jordan

Hi Michael,

Apparently the DMB does not have to be the PDC emulator in W2k3 . Any DC
can do the job, and the first DC to register the 1B special name is the DMB.

See Joe Davies's latest opus "Windows Server 2003 TCP/IP Fundamentals
for Microsoft Windows Appendix C - Computer Browser Service" . The reference
is on page two. There is a bullet for Domain Master Browse Server under the
heading Browsing Collection and Distribution.

There is a further reference down the page, where it says "Only a
computer running Windows Server 2003 that is acting as a domain controller
can perform the Domain Master Browse Server role." It does not specify only
the PDC emulator, just a DC.

http://www.microsoft.com/technet/its...fund_appc.mspx


Michael Giorgio - MVP wrote:
> It helps to understand there are multiple masters, a domain master
> browser (DMB), segment master browser (SMB) and a backup
> master browser (BMB). The DMB or domain master browser is
> always the PDC or PDC emulator for W2k and W2k3, this machine
> will register the domain name 1b unique name which guarentees it will
> be the DMB. The DMB is responsible for gathering the list from all
> SMBs to merge for a domain wide list as well as querying WINS for
> all domain name 1b names in order to obtain their lists. The PDC or
> PDC emulator by default is the SMB for it's local endpoint.
>
> The SMB is responsible for gathering the local list and passing back
> to the DMB as well as making available the domain wide list for all
> clients on it's endpoint. The SMB is elected through a browse
> election process using OS criteria putting DCs higher up the list.
>
> There is a registry value which will give a machine a better chance
> of becoming the SMB, called IsDomainMaster, also an entry which
> prevents the machine from becoming a master browser called
> MaintainServerList. By default all machines including the DMB
> will have an IsDomainMaster setting of false and a MaintainServerList
> setting of Auto. When a machine cannot contact an SMB it will
> force an election in order elect a new master browser. This would
> suggest a communication issue between the SMB all the clients.
>
> When such browse issues occurred in the NT 4.0 it was common
> to turn off browsing on the clients by changing the MaintainServerList
> value to False, this prevents the machine from becoming a master
> browser.
>
> Having said all that it could be a WINS issue or perhaps a multihomed
> master browser as Bill suggested. It could be packet filtering via a
> firewall or router preventing the DMB or SMBs being contacted..
>
>
> <Jordan> wrote in message
> news:(E-Mail Removed)...
>> Hi
>> How is master browser working in a W2K3 environment today?
>> Event viewer logs shows different servers are acting as master
>> browser and the network sniffer reports some broadcast war going on.
>> In early days I remember it was normal to fix master browser to the
>> PDC and deny clients to become a master browser (reg. hack). As far I
>> understand it's just a wins/netbios thing. Who should be preferred as
>> master browser? PDC Emulator?
>> What is best practice today?
>>
>> Jordan

Bill,
How can there be more than 1 machine in any paticular
domain acting as a PDC or emulating a PDC? This would
cause quite a bit of confusion as far as NetBIOS is concerned.
There is no election process for DMB.

The machine holding the PDC eumlator role registers the domain
name 1b entry. Any W2k3 DC can act as the PDC emulator but
that machine must be hold one of the five FSMO roles called "PDC
emulator".

<Snip>

"PDC Emulator - *One master role holder per domain*. The PDC emulator FSMO
role holder is a Windows 2000 DC that advertises itself as the primary
domain controller (PDC) to earlier version workstations, member servers, and
domain controllers. It is also the Domain Master Browser and handles
password discrepancies."

<Snip>
Reference: http://support.microsoft.com/kb/255690/en-us

"Bill Grant" <not.available@online> wrote in message news:
> Hi Michael,
>
> Apparently the DMB does not have to be the PDC emulator in W2k3 . Any
> DC can do the job, and the first DC to register the 1B special name is the
> DMB.
>
> See Joe Davies's latest opus "Windows Server 2003 TCP/IP Fundamentals
> for Microsoft Windows Appendix C - Computer Browser Service" . The
> reference is on page two. There is a bullet for Domain Master Browse
> Server under the heading Browsing Collection and Distribution.
>
> There is a further reference down the page, where it says "Only a
> computer running Windows Server 2003 that is acting as a domain controller
> can perform the Domain Master Browse Server role." It does not specify
> only the PDC emulator, just a DC.
>
> http://www.microsoft.com/technet/its...fund_appc.mspx
>

Below is for W2k3 just in case anyone thinks this has
changed since W2k.

<snip>
..PDC Emulator: The PDC emulator is a domain controller that advertises
itself as the primary domain controller (PDC) to workstations, member
servers, and domain controllers that are running earlier versions of
Windows. For example, if the domain contains computers that are not running
Microsoft Windows XP Professional or Microsoft Windows 2000 client software,
or if it contains Microsoft Windows NT backup domain controllers, the PDC
emulator master acts as a Windows NT PDC. It is also the Domain Master
Browser, and it handles password discrepancies. At any one time, there can
be only one domain controller acting as the PDC emulator master in each
domain in the forest.
<snip>

Reference:
How to view and transfer FSMO roles in Windows Server 2003
http://support.microsoft.com/kb/324801/en-us

"Michael Giorgio - MS MVP" <(E-Mail Removed)> wrote in
message news:(E-Mail Removed)...
> Bill,
> How can there be more than 1 machine in any paticular
> domain acting as a PDC or emulating a PDC? This would
> cause quite a bit of confusion as far as NetBIOS is concerned.
> There is no election process for DMB.
>
> The machine holding the PDC eumlator role registers the domain
> name 1b entry. Any W2k3 DC can act as the PDC emulator but
> that machine must be hold one of the five FSMO roles called "PDC
> emulator".
>
> <Snip>
>
> "PDC Emulator - *One master role holder per domain*. The PDC emulator FSMO
> role holder is a Windows 2000 DC that advertises itself as the primary
> domain controller (PDC) to earlier version workstations, member servers,
> and domain controllers. It is also the Domain Master Browser and handles
> password discrepancies."
>
> <Snip>
> Reference: http://support.microsoft.com/kb/255690/en-us