Open a Port

How do I open a specific port on Windows 2k so that a service can listen for
traffic on that port. I'm developing on win 2k professional and I added the
port # to my services file, but I still can't ping the port. I also ran
netstat -n and the port wasn't in the list.

I don't know much about server/network administration so any advice is
appreciated.

Thanks.

If you are not going out of your way to block a particular port number (such
as a personal firewall running on the target machine) then it should connect
just fine.

You don't "open a port". A running "service" will create the port when it
is executed.

You don't "ping" ports. Port are Layer4,...you ping IP#s which are
Layer3,...two different things. You have to use something like Telnet to
test connecting to something on a particular port number.

You don't connect to ports either,...you connect to running "services" at a
particular port number,...the port# is just a number in the Layer4 portion
of the packet that identifies to the host machine which service you want to
connect to because each service will be associated with a particular "port
number".

You can have multiple services running on the same IP# (Web, FTP, Telnet,
etc.) For any of them you still connect to the same IP#, but is uses the
port number in the Layer4 part of the packet to tell the machine which of
those you wanted to connect to.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com


"Bob Garbados" <(E-Mail Removed)> wrote in message
news:Q2hyd.591$(E-Mail Removed)...
> How do I open a specific port on Windows 2k so that a service can listen
for
> traffic on that port. I'm developing on win 2k professional and I added
the
> port # to my services file, but I still can't ping the port. I also ran
> netstat -n and the port wasn't in the list.
>
> I don't know much about server/network administration so any advice is
> appreciated.
>
> Thanks.
>
>

Thanks Phillip.

Good clarification. I thought that ports were predefined, I didn't realize
that a service creates a port during execution. If I start the service and
can't connect to the service using telnet, I'm guessing that the problem
then lies within the service and that it's not creating the port.


"Phillip Windell" <@.> wrote in message
news:(E-Mail Removed)...
> If you are not going out of your way to block a particular port number
(such
> as a personal firewall running on the target machine) then it should
connect
> just fine.
>
> You don't "open a port". A running "service" will create the port when it
> is executed.
>
> You don't "ping" ports. Port are Layer4,...you ping IP#s which are
> Layer3,...two different things. You have to use something like Telnet to
> test connecting to something on a particular port number.
>
> You don't connect to ports either,...you connect to running "services" at
a
> particular port number,...the port# is just a number in the Layer4 portion
> of the packet that identifies to the host machine which service you want
to
> connect to because each service will be associated with a particular "port
> number".
>
> You can have multiple services running on the same IP# (Web, FTP, Telnet,
> etc.) For any of them you still connect to the same IP#, but is uses the
> port number in the Layer4 part of the packet to tell the machine which of
> those you wanted to connect to.
>
> --
>
> Phillip Windell [MCP, MVP, CCNA]
> www.wandtv.com
>
>
> "Bob Garbados" <(E-Mail Removed)> wrote in message
> news:Q2hyd.591$(E-Mail Removed)...
> > How do I open a specific port on Windows 2k so that a service can listen
> for
> > traffic on that port. I'm developing on win 2k professional and I added
> the
> > port # to my services file, but I still can't ping the port. I also ran
> > netstat -n and the port wasn't in the list.
> >
> > I don't know much about server/network administration so any advice is
> > appreciated.
> >
> > Thanks.
> >
> >
>
>

"Bob Garbados" <(E-Mail Removed)> wrote in message
news:yyiyd.601$(E-Mail Removed)...
> Good clarification. I thought that ports were predefined, I didn't
realize
> that a service creates a port during execution.

Well it is a little "fuzzier" than I explained. The OS's networking system
aknowledges "ports" because the TCP/IP Stack needs to examine the port
number in the packet before it could even know if there was a service using
it or not to start with, but without a running service associated with the
port number to "make it all happen" it becomes meaningless. Just trying to
give you a different way to look at it.

> If I start the service and
> can't connect to the service using telnet, I'm guessing that the problem
> then lies within the service and that it's not creating the port.

That is what I would think. But it can be blocked by using the rudimentary
packet filters the OS has in the Advanced settings of the NIC's TCP/IP
settings. these are found in:

Connection Properties-->TCP/IP Properties-->Options Tab-->TCP/IP
Filtering--Properties.

It can also be block by Personal Firewalls and by ACLs on routers between
subnets.

But in the case of any of those, you would have had to gone out of your way
to do that so there isn't much chance it would be that way by accident.

--

Phillip Windell [MCP, MVP, CCNA]
www.wandtv.com