Foundry Networks Switch and Router Installation And Configuration Manual page 1032

Foundry Switch and Router Installation and Configuration Guide
Layer 3 Filters
Layer 3 filters control a Foundry device's transmission and receipt of packets based on routing protocol
information in the packets. Foundry devices provide the following types of Layer 3 filters:
• IP forwarding filters (same as IP access policies, see "IP Access Policies" on page C-9)
• RIP route filters
• RIP neighbor filters
• IPX forwarding filters
• IPX RIP route and neighbor filters
• IPX SAP service filters
• AppleTalk zone filters
• AppleTalk network filters
• BGP route address filters
• BGP route AS-path filters
• BGP route community filters
• RIP redistribution filters
• OSPF redistribution filters
• BGP redistribution filters
• Router accelerator (IP and IPX switching) filters (same as router acceleration policies, see "Router
Acceleration Policies" on page C-18)
IP Filters
IP filters control the IP packets that the Foundry device sends and receives and the routes that the device learns
or advertises. IP forwarding filters (IP Access policies) control transmission and receipt of IP packets, while RIP
route and neighbor filters control the routes that the device leans or advertises. Route filters filter on specific
network addresses while neighbor filters filter on the IP addresses of the RIP neighbors.
IP Forwarding Filters
IP forwarding filters determine whether to forward or drop an IP packet. IP forwarding filters on a Foundry switch
or router are called "IP access policies". See "IP Access Policies" on page C-9.
RIP Route Filters
RIP route filters control the routes that a Foundry device learns and advertises. Figure C.5 shows an example of
a port with RIP route filters. The port has filters for the inbound direction and the outbound direction. Notice that
the same filter can be used for both directions. The inbound filters control the routes that the device learns;
denied routes are not learned by the device. Outbound filters control the routes that the device advertises; denied
routes are not advertised to RIP neighbors.
C - 28 December 2000