Check the Listening ports in AIX

To Determine which processes have listening ports on AIX

 The open source "lsof" tool is great for determining what process has a port open.  Unfortunately lsof isn't included with AIX so if you just want to quickly identify which process is using a port and you don't have lsof you can use "netstat -Aan" combined with the "rmsock" command.  

For example, lets say I want to identify which process is listening on port 1334.   I would first run:

# netstat -Aan | grep LISTEN | grep 1334

f100050000b05bb8 tcp4       0      0  *.1334      *.*  LISTEN

The socket 0xf100050000b05808 is being held by proccess 5767378 (writesrv).
You can see that port 1334 is open by the writesrv process with PID 5767378.
You then take the first column (f100050000b05bb8 in this example) and run the following command:
# rmsock f100050000b05bb8 tcpcb
  

If you want to see all of the TCP listening ports and which processes and PID's are assigned to them, run the following script:

!/usr/bin/ksh

print "Port            PID              Process"
netstat -Aan | grep LISTEN | awk '{print $1 " " $5}' | while read pcb port; do 
        out=`rmsock $pcb tcpcb`
        if echo "$out" | grep "Kernel Extension" > /dev/null; then
                printf "%-15s Kernel Extension\n" "$port"
        else
                pid=`echo "$out" | sed -n 's/.*pro[c]*ess \([0-9][0-9]*\) .*/\1/p'`
                if [ -n "$pid" ]; then
                        proc=`ps -p $pid | tail -n 1 | awk '{print $4}'`
                        printf "%-15s %-16s $proc\n" "$port" $pid
                else
                        echo "Error, Line not recognized \"$out\" for Port $port"
                fi
fi
done

Here is example output from the script:

*.13            4063356          inetd

*.21            4063356          inetd

*.23            4063356          inetd

*.25            1835206          sendmail

*.37            4063356          inetd

*.24575         15597582         java

*.111           Kernel Extension

*.199           3539070          snmpdv3ne

*.49293         35389582         rwrun

*.512           4063356          inetd

*.513           4063356          inetd

*.514           4063356          inetd

*.25075         15597582         java

*.657           6095060          rmcd

192.168.1.32.12360 51052606         java

*.25575         15597582         java

*.1334          5570768          writesrv

*.1536          22610158         tnslsnr

*.1641          34472056         tnslsnr

*.2049          Kernel Extension

192.168.1.23.38199 20316174         java

192.168.1.25.39654 25559104         java

*.4458          6750376          httpd

*.6000          5373952          X

*.6000          5373952          X

*.6001          6619338          X

*.6001          6619338          X

*.6112          4063356          inetd

*.55731         Kernel Extension

127.0.0.1.52089 34472056         tnslsnr