Use add filters ip forward system to add filters to all interfaces receiving packets. When you apply system filtering, you must specify both the destination and the source IP addresses. The masks provide a range of IP addresses for matching purposes. The addresses are used for comparison to the filter entry. The protocol type and port ID, are also used to match filtering criteria. The IP addresses you provide are compared to the IP packet address. If the address, protocol type, and port ID match patterns in the filter, then filtering is applied.