3Com 3C840 manual 2Advertisement Filters

Filtering Capabilities 12-3

Table 12–1	Data Filters
Filter	Action
IP	Controls network access based on the protocol and source/destination
	address. IP filter rules allow filtering based on the source address,
	destination address, protocol type, source port, and port designation of
	the IP packet.
IPX	Controls network access based on the protocol and source/destination
	network. IPX filter rules allow filtering based on the source network,
	destination network, protocol type, source socket, destination socket,
	source node, and node designation of the IPX packet.
Bridge	Controls network access based on the source and destination MAC
	addresses.

Advertisement Filters Advertisement filters operate on network protocol packets that contain varying information such as SAP or RIP. Filtering of these packets is performed by the specific protocol process. The following table describes the advertisement filters supported:

Table 12–2Advertisement Filters

Filter	Action
IP-RIP	Controls the content of IP Routing Information Protocol (RIP) packets that
	are sent out or received on specific ports. The IP RIP filtering process
	filters addresses from the RIP packet upon transmission, and does not
	enter routes into the routing table upon receipt.
IPX-SAP	Controls the content of Service Advertising Protocol (SAP) packets that
	are sent out or received on specific ports. The IPX-SAP filter rules allow
	filtering on service type, server name, network address, node address,
	and socket number fields of the service entry. The forwarding process
	uses the filter information to prevent the service information from being
	included in the SAP packet.
IPX-RIP	Controls the content IPX RIP packets that are sent out or received on
	specific ports. The IPX RIP filtering process filters addresses from the RIP
	packet upon transmission, and does not enter routes into the routing
	table upon receipt.

Generic Filters Generic filters are protocol-independent and are specified by byte and offset values in a packet. Packets are filtered by comparing each packet's offset value and byte information with the values that you define in the filter. The router will accept or reject the packet based on the result.