Changes

:* '''Rules are applied to: ''' '''chains''' (e.g. ''input/output''), '''protocols''' (e.g. ''tcp/udp/icmp''), and '''ports''' (e.g. ''22, 80, 443'').== ::# For the ''request '', the '''source port (sport) is 40112 ''' and the '''destination port (dport) is 80''' ==::# For the ''response '' the '''source port is 80 ''' and the '''destination port is 40112'''::# Because we have Since the '''RELATED,ESTABLISHED ''' rule already exists, we are only care concerned about controlling the '''incoming traffic on the server''', which in our example on , the server '''chain is : INPUT TCP ''', the '''protocol is: tcp''', and the '''destination is: port 80'''.