To find duplicate IP, you can create a text file and putting all the IP addresses into it and seperate them with line break. eg: Create a text file called ip.txt [root@www ~]# touch ip.txt Put all the ip into the file and save it [root@www ~]# vi ip.txt 192.168.1.22 192.167.1.22 192.168.1.23 192.168.1.23 192.168.1.70 192.168.1.88 [...]