Solaris: How to check which process is holding the port

Most of the time, we are in a situation as to how to find the process which is holding the same port cause the application issues. This post will help us whenever we are in same position. Yes, we can find the  process with using port in different methods. Let we start to search it.....

root@unixrock # ndd /dev/tcp tcp_listen_hash

TCP zone IP addr port seqnum backlog (q0/q/max)

----skipped------

281 ffffffff81d46440 0 ::ffff:127.0.0.1 00025 00000000 0/0/16

----skipped------

from the above output we can find the process of the port 25, please follow the below steps

root@unixrock # mdb -k

Loading modules:[unix krtld genunix specfs dtrace cpu.generic uppc pcplusmp ufs md mpt ip hook neti sctp arp usba fctl nca lofs audiosup cpc fcip random crypto zfs logindmux ptm sppp sata nfs]

>

> ffffffff81d46440::print tcp_t tcp_rq

tcp_rq = 0xffffffff8961f028

>

> 0xffffffff8961f028::q2stream

ffffffff87052e10

>

> ffffffff87052e10$ 0xffffffff874bc780::whereopen

file ffffffff893689d8

ffffffff88dc8900

>

> ffffffff88dc8900::ps

S PID PPID PGID SID UID FLAGS ADDR NAME

R 935 1 935 935 0 0x52010000 ffffffff88dc8900 sendmail

>

root@unixrock #

Yes !!! we have found the process (sendmail) which using the port 25

we can use lsof utility to find the process with using port. although lsof will not be available on all solaris server, we have to install the lsof package. NOTE : This utlity can't be used in Non-global zones.

root@unixrock # /usr/local/bin/lsof -i :25

lsof: WARNING: access /.lsof_unixrock: No such file or directory

lsof: WARNING: created device cache file: /.lsof_unixrock

COMMAND PID USER FD TYPE DEVICE SIZE/OFF NODE NAME

sendmail 935 root 5u IPv4 0xffffffff81d46240 0t0 TCP localhost:smtp (LISTEN)

root@unixrock #

Yes, we have found the process with using port by using lsof utility.

Now our concern would be how to check the process with using port in non-global zone level. Yes, we have the option to do that by using our customized script. Please follow the steps... 

root@unixrock # cat /var/tmp/check_port.sh

#!/bin/ksh

 

CODE='---------------------------------------------'

PID=$(/usr/bin/ps -ef | sed 1d | awk '{print $2}')

 

if [ $# -eq 0 ]; then

read PORT?"Enter port you would like to know pid for: "

else

PORT=$1

fi

 

for f in $PID

do

/usr/proc/bin/pfiles $f 2>/dev/null | /usr/xpg4/bin/grep -q "port: $PORT"

if [ $? -eq 0 ]; then

echo $CODE

echo "Port: $PORT is being used by PID:\c"

/usr/bin/ps -ef -o pid -o args | egrep -v "grep|pfiles" | grep $f

fi

done

exit 0

root@unixrock #

Copy the script and executed as mentioned below 

root@unixrock # /var/tmp/check_port.sh

Enter port you would like to know pid for: 25

---------------------------------------------

Port: 25 is being used by PID: 935 /usr/lib/sendmail -bl -q15m

root@unixrock #

Yes...We have found the process with using the port by executing customized scripts.

I hope this post will help you all. If I found some other way, I will share with you all for the same.

Thanks for reading this post. Please leave your valuable comments and queries.