Adding a null route to a host on linux
This is done by adding the following line to the /etc/sysconfig/static-routes file:
any host 111.111.111.111 reject (being 111.111.111.111 the ip address to block)
When you perform a “route -n” you will see this IP with “-” as it’s gateway. This will cause your server to drop all response traffic to this IP.
