We are studying iptables for a Computer Systems Security course. We are confused as to what happens when the -s
and -d
arguments are both used in the same rule, such as:
iptables -A OUTPUT -s 10.7.53.2 -d 10.7.53.5 -j REJECT
We know how to block ports coming in and going out as well as ip addresses. However, we are unsure as to what the line above does.
At first we thought it blocks output from one ip address to another, but when we tested this theory we found the assumption was invalid.