You may execute a reverse DNS lookup to determine a hostname you want to block.
Use a web service like reverse DNS lookup or 'nslookup' to get a hostname.
Terminal.app and enter
- At the prompt enter
server 220.127.116.11 (this defines which dns-server to use to do the reverse DNS lookup. 18.104.22.168 is a google name server)
- At the next prompt enter an ip-address
- Now you'll get the host name you need for your
> server 22.214.171.124
Default server: 126.96.36.199
188.8.131.52.in-addr.arpa name = p5DDC6637.dip0.t-ipconnect.de.
If you add
127.0.0.1 p5DDC6637.dip0.t-ipconnect.de to your
hosts file you will prevent your computer accessing my web server.
A lot of ip-addresses and correspondent host names can't be tied to a special computer/host. Mine change at least every 24 hours.
A today hazardous site/hostname might be a valuable one in the future but unaccessible for you.
Some ip-addresses are tied to several hostnames with the consequence that you won't be able to detect the name you actually want to block.