IP Filtering Examples

These examples will help you understand how to use the IP Filtering feature.

IP Filtering Example 1

Allow connections from IP address 215.43.21.12 and the network 192.168.0.0, and deny all other connections.

ALLOW 215.43.21.12
ALLOW 192.168.0.0 (255.255.0.0)

-or-

ALLOW 192.168.*
DENY:*

IP Filtering Example 2

Allow connections from IP address 215.43.21.12 and the network 192.168.0.0, but not from the address 192.168.0.12, and deny everything else.

ALLOW 215.43.21.12
DENY 192.168.0.12
ALLOW 192.168.0.0 (255.255.0.0)

-or-

ALLOW 192.168.*
DENY.*

Note: Denying the connection from 192.168.0.12 comes before allowing connections to the 192.168.0.0 network. If the host was to find the ALLOW item first, it would let IP address 192.168.0.12 through, since it matches the condition. To prevent this, the address 192.168.0.12 is checked before the network to which it belongs.

IP Filtering Example 3

Allow all connections, except those coming from 192.168.0.12

DENY:192.168.0.12

IP Filtering Example 4

Deny all connections from the network 192.168.0.0 except for the subnet 192.168.12.0; allow all other connections

ALLOW:192.168.12.0(255.255.255.0)

-or-

ALLOW:192.168.12.*
DENY:192.168.0.0 (255.255.0.0)

-or-

DENY:192.168.*

Article last updated: 27 September, 2022