Hiding instances on the n/w (Port 1434)

Hi,
I tried to hide an instance of MSSQL2000 SP3 on the n/w by first removing
all the enabled protocols using the server network utility which worked fine,
i then renabled the TCP/IP protocol and selected hide server which seemed to
switch the port number to 2433, which i understand has an implication for
clients regarding connection strings including port numbers, aliasing etc.
I then switched the port number back to 1433 and de-selected the hide server
option but now i can connect to the machine using query analyzer when i know
the machine name but if i try to hit the button which lists all servers on
the n/w the server does not appear. I believe this list is populated based on
a n/w port scan which builds the list based on machines that respond to a
request on UDP port 1434.
If anyone knows why the server will not appear i would appreciate a pointer,
i have also attempted to find help about blocking on port 1434 but cannot
find help on how to do so, keep getting instructions on blocking at the
firewall, i just want to understand how this works.
Thanks in advance
Pat
Pmcg,
You cannot prevent SQL Server listening on port 1434. If you want to prevent
clients accessing this port, you have no choice but to use a firewall.
SQL Server's enumeration mechanism can only list servers that are registered
in Enterprise Manager, and ones that are on your subnet - the broadcast does
not work across routers or firewalls. Perhaps this is the problem.
Mark Allison, SQL Server MVP
http://www.markallison.co.uk
Looking for a SQL Server replication book?
http://www.nwsu.com/0974973602m.html
"Pmcg" wrote:

> Hi,
> I tried to hide an instance of MSSQL2000 SP3 on the n/w by first removing
> all the enabled protocols using the server network utility which worked fine,
> i then renabled the TCP/IP protocol and selected hide server which seemed to
> switch the port number to 2433, which i understand has an implication for
> clients regarding connection strings including port numbers, aliasing etc.
> I then switched the port number back to 1433 and de-selected the hide server
> option but now i can connect to the machine using query analyzer when i know
> the machine name but if i try to hit the button which lists all servers on
> the n/w the server does not appear. I believe this list is populated based on
> a n/w port scan which builds the list based on machines that respond to a
> request on UDP port 1434.
> If anyone knows why the server will not appear i would appreciate a pointer,
> i have also attempted to find help about blocking on port 1434 but cannot
> find help on how to do so, keep getting instructions on blocking at the
> firewall, i just want to understand how this works.
>
> Thanks in advance
> Pat