ENHANCED INTERNET PACKET ROUTING LOOKUP

• US 20010012295A1
• Filed: 08/22/1997
• Published: 08/09/2001
• Est. Priority Date: 08/22/1997
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: WILFORD, BRUCE A
• Granted Patent: US 6,512,766 B2
• Time in Patent Office: Days
• US Class Current: 370/392
• CPC Class Codes: H04L 45/00 Routing or path finding of packets in data switching networks routing or path finding in wireless networks H04W40/00
• CPC Class Codes: H04L 45/50 using label swapping, e.g. multi-protocol label switch [MPLS]
• CPC Class Codes: H04L 45/742 Route cache; Operation thereof
• CPC Class Codes: H04L 69/22 Parsing or analysis of headers

Abstract

The invention provides a method and system for routing information lookup for packets using routing protocols such as IP or IP multicast (IGMP), or MPLS (multiprotocol label switching, also known as tag switching or label switching) or MPLS multicast, in which both the destination address and the length of that destination address are matched using a lookup table having separate entries for selected addresses and their lengths, which can be accessed in parallel for multiple representations of destination addresses, and in which the input interface associated with the packet is included in the information used for matching.

Claims

1. A method, including the steps of receiving a packet header, said packet header including header information;

determining a packet treatment identifier responsive to said header information, said packet treatment identifier including an input interface identifier;

using said packet treatment identifier to access a memory having information regarding treatment of packets, said information being responsive to said input interface identifier.

2. A method as in

claim 1

, wherein said memory includes a plurality of entries matching said header information and differing with regard to said input interface identifier.

3. A method as in

claim 2

, wherein said memory includes a plurality of entries matching said header information and responsive to a multicast packet.

4. A method as in

claim 3

, wherein said multicast packet is encapsulated using an MPLS protocol.