Netopia 4753 2A4NA Administration Manual page 195

Example 2
Filter Rule:
Incoming packet has the source address of 200.1.1.184.
IP Address
200.1.1.184
AND
255.255.255.128
This incoming IP packet (10000000) has a source IP address that does not match the network address in the
Source IP Address field (00000000) in the Netopia 4753. This rule will forward this packet because the packet
does not match.
Example 3
Filter Rule:
Incoming packet has the source address of 200.1.1.184.
IP Address
200.1.1.184
AND
255.255.255.240
Since the Source IP Network Address in the Netopia 4753 is 01100000, and the source IP address after the
logical AND is 1011000, this rule does not match and this packet will be forwarded.
200.1.1.0
255.255.255.128
Forward = No
Binary Representation
10111000
10000000
10000000
200.1.1.96
255.255.255.240
Forward = No
Binary Representation
10111000
11110000
10110000
(Source IP Network Address)
(Source IP Mask)
(What happens on match)
(Source address in incoming IP packet)
(Perform the logical AND)
(Logical AND result)
(Source IP Network Address)
(Source IP Mask)
(What happens on match)
(Source address in incoming IP packet)
(Perform the logical AND)
(Logical AND result)
Security 13-25