Sql Server Browser Service

1) Sql server browser runs  as a windows application on the machine, listening for the incoming request calls from client applications.

2) sql server 2000 & later versions support multiple instances of sql server on same machine

3) If the client protocol is tcp/ip, then default installation run on 1433 port
   if the client protocol is named pipe, then it runs under default pipe.

4) when more than one instance is installed on the machine then sql server browser by default listens on  udp port 1434 for client requests.

5) sql server browser looks up the registry & lists all the instances  & the port under which they are running.

6) client request are received by browser & returns the valid port number of the instance , client network protocol manages to call the instance back with the port number.

7) client can connect to correct instance with a valid port number even with out having a browser  on the server

8) sql server 2000 service by default plays the role of browser as it doesnt have a feature of browser service

9) browser service is provided by 2005 & later versions

10) if sql server 2000 & later versions are installed on same machine, then it is advised to upgrade sql server 2000 to sp3 , otherwise the port 1434 is used by sql server 2000 &  2005 fails to get the port.

11) if sql server 2000 is not upgraded to sp3 , then it should be turned off while 2005 or later versions are installed that way they don't fight for port 1434.

12) sql server browser recieves unauthenticated request, so it should be run under user  with  least privileged  roles.