topic Re: Unable to connect to port 12789 in Operating System - HP-UX

Unable to connect to port 12789

dhanish — Fri, 11 Jan 2002 04:47:12 GMT

HI ,
I am trying to run one engine on the port 12789 .but it says Unable to connect to the port 12789 ,port may be in use by another server.But when i see netstat -a and /etc/services this port is not listed anywhere.Any clues ??

Re: Unable to connect to port 12789

K.Vijayaragavan. — Fri, 11 Jan 2002 05:18:45 GMT

Hi,

You may have to see the file /etc/rpc also as some of the ports are defined here.

You can even check the /etc/inetd.conf.

you can use the command #rpcinfo

-vijay

Re: Unable to connect to port 12789

Tee How Long — Fri, 11 Jan 2002 06:38:35 GMT

Does your engine require u to create the entry in /etc/services ?

Re: Unable to connect to port 12789

Robin Wakefield — Fri, 11 Jan 2002 08:31:41 GMT

Hi,

Are you running "netstat -an" rather than "netstat -a", otherwise the port may show up by its name if it's in /etc/services.

Also, you could run

lsof -i tcp:12789

or

lsof -i udp:12789

if you have this utility.

Rgds, Robin.

Re: Unable to connect to port 12789

rick jones — Fri, 11 Jan 2002 19:06:08 GMT

/etc/services does _not_ "physically" reserve a port number. it is merely there as a convenience for us humans - allowing us to refer to services by names rather than port numbers.

if the software is trying to setup its listen endpoint, it should not use the word "connect" in its error messages as that implies it is trying to call connect() rather than bind() which is what would appear to be the socket call it would be making. using tusc against the app while it is starting would help confirm what socket calls it is making.

the suggestions about remembering to use -n in netstat when checking the output for the port number is good.

if you do find that there is an old connection still there, in any state other than LISTEN, it indicates that the software you are trying to start is broken and is not setting SO_REUSEADDR via setsockopt() prior to calling bind().

if the endpoint is in the LISTEN state it means that you _have_ to kill the still running older instance of the application.

in 99 situations out of 10, it is _not_ apropriate to use ugly hacks to arbitrarily abort endpoints out from under the application...