Netopia 4000-Series manual Example

Security 10-43

255.255.255.240	11110000	(Perform the logical AND)
	10110000	(Logical AND result)

Since the Source IP Network Address in the Router is 01100000, and the source IP address after the logical AND is 1011000, this rule does not match and this packet will be forwarded.

Example 4

		Filter Rule:		200.1.1.96		(Source IP Network Address)
				255.255.255.240		(Source IP Mask)
				Forward = No		(What happens on match)
Incoming packet has the source address of 200.1.1.104.
	IP Address			Binary Representation
	200.1.1.104		01101000		(Source address in incoming IP packet)
	AND
	255.255.255.240		11110000		(Perform the logical AND)
			01100000		(Logical AND result)

Since the Source IP Network Address in the Router is 01100000, and the source IP address after the logical AND is 01100000, this rule does match and this packet will not be forwarded.

Example 5

		Filter Rule:		200.1.1.96		(Source IP Network Address)
				255.255.255.255		(Source IP Mask)
				Forward = No		(What happens on match)
Incoming packet has the source address of 200.1.1.96.
	IP Address			Binary Representation
	200.1.1.96		01100000		(Source address in incoming IP packet)
	AND