why is port 2289 open, should i block it, and how?

Thanks for your question.

You can use this command in a terminal to know which application is using this port (maybe you need to install the lsof package):
lsof -i:2289

thanks Hanusz for your response.
checked by typing 'man lsof' so it is installed and read through some command options.
applied lsof -i:2289
the command responded with nothing.
so i tried lsof -i:80 just to see what it would show, if i have my firefox browser running and connected to launchpad.
nothing again.

so am still clueless.

?
niyam

It is normal that lsof -i:80 shows nothing because the port 80 is open on the launchpad server, not your computer.

What is the result of the "netstat -t" command ?

I'm curious how you know your port is open? Did you run netstat in a terminal or did you use a web site to scan your ports? I would try the Shields up web site. You can scan the common ports or specify a port.

https://www.grc.com/x/ne.dll?bh0bkyd2

If it reports that 2289 is open then you are probably port forwarding on your router/modem (assuming you are on broadband). Shield's up reports that 2289 is stealth for me (which I expected since I'm not forwarding it). I am forwarding a different port for bit torrent and if the application is not running Shields up reports it "closed" (not stealth because I'm forwarding but no app is listening) and if the application is running then the port is reported as "open".

I would try Shields up site and see what you find. If port 2289 is reported open then some app is using it and you are forwarding it (in which case it might be good to figure out what it is). If it's stealth, then I wouldn't worry. It's probably just related to the NAT feature of your router.

Hope that helps.