Kill a port

[NetworkGhost]

Is there a way to Kill a port that remains open or hangs after the process that uses it has been killed?

 

[coffeysm]

What kind of program is it? (ie: inetd startup, standalone, etc..)

 

[edfair]

Possibly disable then enable.

Ed Fair
Give the wrong symptoms, get the wrong solutions.

 

[NetworkGhost]

I am not to familiar with Unix but it is a Licensing Application

 

[coffeysm]

Odds are if the port is not closing down, there is a process still running. I would look into the lsof command or netstat -na.

 

[PHV]

As last resort reboot the unix box, and avoid to kill a licensing app...

Hope This Helps, PH.
Want to get great answers to your Tek-Tips questions? Have a look at FAQ219-2884 or FAQ181-2886

 

[jgtyler]

I have the same problem in the past with a database program, the manufactor said that the only way to release the port was to reboot. Not the best answer, but it worked.

 

[NetworkGhost]

Reboot is definitly not an option.

 

[coffeysm]

What program is using the port?

 

[tonykent]

I had a similar problem recently with a database which refused to release a port on my HPUX 11 server. Our unix admins were unable to come up with a solution so I spent some time browsing for a solution. I found the following:

"Find the TCP instance data and then use tcp_discon to remove the instance as follows:

# ndd -get /dev/tcp tcp_status
TCP dest snxt suna swnd cwnd rnxt rack rwnd rto mss [lport,fport] state

0183b8b4 015.043.233.086 533cb8ce 533cb8ce 00008000 00003000 533bc583 533bc583
00000000 02812 04096 [c00a,cea9] TCP_CLOSE_WAIT

So, if you wanted to remove this connection:
# ndd -set /dev/tcp tcp_discon 0x0183b8b4

If you want to use the tcp_discon_by_addr, you use a 24 byte string that contains the hex representation of the quadruple.

For example, if the connection that I want to delete is:

Local IP: 192.1.2.3 (0xc0010203)
Local Port: 1024 (0x0400)
Remote IP : 192.4.5.6 (0xc0040506)
Remote Port: 2049 (0x0801)

The "hex" string you pass to tcp_discon_by_addr is:

# ndd -set /dev/tcp tcp_discon_by_addr "c00102030400c00405060801"

NOTE: the preceding 0x that typically indicates a Hex number is NOT part of the string passed"

I have as yet been unable to test this out for myself so I cannot confirm that it works. If you manage to substantiate it please do let me know!

 

[pcunix]

ndd-set seems to be a Solaris only thingie?

Tony Lawrence
Linux/Unix/Mac OS X Resources

http://aplawrence.com

 

[tonykent]

The information given in my previous post is taken from the HP forum site and relates specifically to HPUX. I can post the link if that is allowed.

 

[pcunix]

Of course it's allowed. That ndd-set looks very useful; can't think of anything quite like it on other Unixes. I did find it on Solaris, was surprised not to find it in Unixware (Solaris and Unixware are very similar). Good to know it's in HPUX.

Tony Lawrence
Linux/Unix/Mac OS X Resources

http://aplawrence.com

 

[tonykent]

Fine. The information above came from the following discussion:

http://forums1.itrc.hp.com/service/...493758+1115980508630+28353475&threadId=106791

There is also:

http://forums1.itrc.hp.com/service/...0.html&admit=716493758+1115981481775+28353475

If you manage to confirm that this does work please let me/us know. Thanks.