IP tables confusion - Securing the Environment lesson

So in the IP Table “Securing the Environment lesson” , there is a rule that allows incoming traffic in port 80 from the source for caleston-lp10 (172.16.238.187). My question is why is this rule made or even needed when the default rule is to allow all traffic? There was no rule added to drop any port 80 traffic, so this seems useless. Im confused as to why even add it?

@ordep81, we are only allowing all outgoing connections from port 80. Incoming connections are blocked. So we need to allow incoming connections on port 80.

I don’t see where all incoming is blocked for port 80, probably why I’m confused. As well as the lesson mentioned that default rule was to allow all incoming traffic, which is why the Drop rule was added for port 22?

Hello @ordep81
iptables is set to DROP incoming traffic, through the default input policy, and you want to selectively allow traffic in

In 1:30sec into the lesson it says that “client B goes through the default policy which accepts all input connections” Is this a mistake?

If the default rule was set to block all traffic, then DBAPP01 would now need a input rule from DEVDB01 to accept traffic. Correct me if im wrong, just trying to understand.

Hello @ordep81
In the first example you have mentioned , because when we allow the outgoing connection to port 80 to caleston-repo-01 , as you said by default it will make other than “caleston-repo-01” allowed also, we need then to drop all outgoing connections to ensure that only the source or destination chosen will be allowed not all (so the default now is cancelled for port 80) then if we need to allow the incoming on port 80 we have to allow it with another rule.