I have been hired to do some tests on networks but however everytime i do a scan every port is open. This is using nmap and homemade tools. This has been a ongoing problem. I created a script to check random IPs and results were that every port was open on every address. Going around the web i see a few people have the same problem. How am I supposed to do my job and get an accurate scan on a remote network. This is a new problem as i never encountered this problem up until a few months ago.
Can any one give me reasons why every scan every port is showing as open. Even though doing nc ip port shows that it is infact not open.
Could this be my ISP? or any other reason?
