I am using the following command to output IPs from live tcpdump capture
sudo tcpdump -nn -q ip -l | awk '{print $3; fflush(stdout)}' >> ips.txt
I get the following output
192.168.0.100.50771
192.168.0.100.50770
192.168.0.100.50759
Need 2 things:
Thank you in advance
To extract unique IPs from tcpdump you can use:
awk '{ ip = gensub(/([0-9]+.[0-9]+.[0-9]+.[0-9]+).*/,"\\1","g",$3); if(!d[ip]) { print ip; d[ip]=1; fflush(stdout) } }' YOURFILE
So your command to see unique IPs live would be:
sudo tcpdump -nn -q ip -l | awk '{ ip = gensub(/([0-9]+.[0-9]+.[0-9]+.[0-9]+)(.*)/,"\\1","g",$3); if(!d[ip]) { print ip; d[ip]=1; fflush(stdout) } }'
This will print each IP to output as soon as they appear, so it cannot sort them. If you want to sort those, you can save the output to a file and then use sort
tool:
sudo tcpdump -nn -q ip -l | awk '{ ip = gensub(/([0-9]+.[0-9]+.[0-9]+.[0-9]+)(.*)/,"\\1","g",$3); if(!d[ip]) { print ip; d[ip]=1; fflush(stdout) } }' > IPFILE
sort -n -t . -k 1,1 -k 2,2 -k 3,3 -k 4,4 IPFILE
Example output:
34.216.156.21
95.46.98.113
117.18.237.29
151.101.65.69
192.168.1.101
192.168.1.102
193.239.68.8
193.239.71.100
202.96.134.133
NOTE: make sure you are using gawk. It doesn't work with mawk.