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Firewall Tutorial
Source IP Address = 199.211.211.17
Source IP address mask = 255.255.255.255
Destination IP Address = 0.0.0.0
Destination IP address mask = 0.0.0.0
Using the tables on page 158, find the destination port and protocol numbers (the local
Telnet port):
Protocol = TCP (or 6)
Destination Port = 23
The filter should be enabled and instructed to block the Telnet packets containing the
source address shown in step 2:
Forward = unchecked
This four-step process is how we produced the following filter from the original rule: