Get count of IP addresses in a log file arranged in descending order of frequency

<yambe:breadcrumb>Useful_bash_shell_scripts|Useful bash shell scripts</yambe:breadcrumb>

Get count of IP addresses in a log file arranged in descending order of frequency

To get count of IP addresses in a log file arranged in descending order of frequency use following steps:

1. Get all the IPs from log file into a temporary file:

   grep -o '\([0-9]\{1,3\}\.\)\{3\}[0-9]\{1,3\}' log-file > ip1.txt

2. Remove set of IPs that are not important such as loop-back or machines own IP address or local IP ranges

   grep -v 127.0.0.1 ip1.txt | grep -v 1.2.3.4 | grep -v '^192\.168' > ip2.txt

3. Sort IPs, get count of each IP with help of "uniq -c" and then again sort in reverse order of frequency using sort:

   cat ip2.txt | sort | uniq -c | sort -rnb > ip3.txt

4. Final temporary file (eg ip3.txt in above command) would have IPs arranged in descending order of frequency with frequency also mentioned in front of each IP