Filtering Example #2 - Netopia 2200 series Software User's Manual

Filtering example #2

Suppose a filter is configured to block all incoming IP packets with the source IP address of
200.233.14.0, regardless of the type of connection or its destination. The filter would look
like this:
This filter blocks any packets coming from a remote network with the IP network address
200.233.14.0. The 0 at the end of the address signifies any host on the class C IP net-
work 200.233.14.0. If, for example, the filter is applied to a packet with the source IP
address 200.233.14.5, it will block it.
In this case, the mask, must be set to 255.255.255.0. This way, all packets with a source
address of 200.233.14.x will be matched correctly, no matter what the final address byte
is.
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Note:
The protocol attribute for this filter is Any by default. This tells the filter to
ignore the IP protocol or type of IP packet.