
Security 
Example network
Incoming
Packet Filter
Netopia
Internet
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  | IP: 200.1.1.??  | ||
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Example filters | 
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Example 1 | 
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  | Filter Rule:  | 
  | 200.1.1.0  | 
  | (Source IP Network Address)  | 
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  | 255.255.255.128  | 
  | (Source IP Mask)  | 
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  | Forward = No  | 
  | (What happens on match)  | 
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Incoming packet has the source address of 200.1.1.28  | 
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  | IP Address  | Binary Representation  | 
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  | 200.1.1.28  | 00011100  | (Source address in incoming IP packet)  | ||||||
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  | 255.255.255.128  | 10000000  | (Perform the logical AND)  | ||||||
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  | 00000000  | (Logical AND result)  | |||||
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This incoming IP packet has a source IP address that matches the network address in the Source IP Address field (00000000) in the Netopia 4553. This will not forward this packet.