NetComm G.SHDSL 4-port Security Modem Routers NB712 - Manual (Page 55)

NB712 / NB714 User Guide 55
YML829 Rev1
Rule Order
The order of the rules affects the filtering result. The filtering process will proceed from top to bottom, changing
the order will give a different result. For example:
Rule Source Address Destination Address Action
A 10.0.0.0 172.16.6.0 Permit
B 10.1.99.0 172.16.0.0 Deny
C Any Any Deny
Where “0” at the last eight bits indicates “from 1 to 254”, “0” at any eight bits preceding “0”, “0.0” or “0.0.0”
indicates “from 1 to 254”. On the other hand, “0” and all “0” successive with “0” represents any.
When the rule is ordered as ABC.
Index Source Address Destination Address Action
1 10.1.99.1 172.16.1.1 Deny (B)
2 10.1.99.1 172.16.6.1 Permit (A)
3 10.1.1.1 172.16.6.1 Permit (A)
4 10.1.1.1 172.16.1.1 Deny (C)
5 192.168.3.4 172.16.6.1 Deny (C)
The rule order will permit 10.1.99.1 to access 172.16.6.1.
When the rule is ordered as BAC.
Index Source Address Destination Address Action
1 10.1.99.1 172.16.1.1 Deny (B)
2 10.1.99.1 172.16.6.1 Deny (B)
3 10.1.1.1 172.16.6.1 Permit (A)
4 10.1.1.1 172.16.1.1 Deny (C)
5 192.168.3.4 172.16.6.1 Deny (C)
The rule order will deny 10.1.99.1 to access 172.6.6.1.