Destination Address
The address given here is compared to the destination address of the packet. Note that only the part of the address specified by the mask field is used in the comparison. If a match is found, the packet is forwarded (rules containing permit) or discarded (rules containing deny).
The following rule example denies destination addresses that match the first 8 bits of the given IP address (that is, addresses beginning with 192):
deny 0.0.0.0/0 192.77.200.203/8
Masks
These fields specify the number of bits to be used in the source address and destination address comparisons. Valid values are
0Match packets with any IP address. The contents of the source address or destination addr ess field are not important.
8Compare the first byte (octet) in the IP addresses.
16Compare only the first two bytes of the IP addresses
24Compare only the first three bytes of the IP Addresses
32Match the entire IP address
The masks are separated from source address and destination address by forward slashes (/).