Method and device for generating message search key value

Abstract

The present invention discloses a message seek key value generation method and device. The method comprises the steps of: dividing fields obtained through message analysis to five groups; seeking a TCAM (Ternary Content Addressable Memory) according to the forwarding information of the message to obtain selectors corresponding to the field groups; selecting the fields with a corresponding quantityby the selectors, and splicing the fields to form a first key value, a second key value, a third key value, a fourth key value and a fifth key value; splicing the second key value and the first keyvalue to a sixth key value, and splicing the fifth key value, the fourth key value and the third key value to a seventh key value; splitting the sixth key value to a plurality of 16 bits, and selecting a plurality of 16 bits by preset selectors to splice the plurality of 16 bits to an eighth key value; splitting the eighth key value to a ninth key value and a tenth key value, and splicing the seventh key value and the ninth key value to an eleventh key value, employing the preset selectors to select a plurality of 1 bits, 2 bits and 4 bits, and splicing the 1 bits, the 2 bits and the 4 bits toa twelfth key value; and splicing the twelfth key value and the tenth key value to a message seek key value. The message seek key value generation method and device can effectively employ the TCAM resource when the TCAM is applied to ACL (Access Control List).

Description

technical field [0001] The invention relates to the technical field of computer networks, in particular to a method and device for searching key values ​​in messages. Background technique [0002] With the expansion of network scale and the increase of traffic, the control of network security and the allocation of bandwidth have become important contents of network management. Filtering packets can effectively prevent illegal users from accessing the network, and can also control traffic and save network resources. An ACL (Access Control List, Access Control List) is often used to filter packets, which is an ordered set of rules, and packets are filtered through these rules. When the port of the device receives the message, the current port analyzes the message according to the applied ACL rules, and allows or prohibits the message to pass according to the preset rules. ACL can pass the source address, destination address, port number, etc. of the message. Filter packets. ...

AI Technical Summary

Problems solved by technology

In actual deployment and use, since the configuration combination of the end user cannot be known, usually the ACL lookup key (Key) can only be divided into three types: 160bit, 320bit and 640bit, but in actual deployment and use, the field information that really needs to be matched , there are actually very few unique lookup keys. For example, most applications only need IPv4 source addresses. Since the IPv4 source address is only 32 bits, a TCAM with a width of 80 bits is sufficient, but using a 160-bit Key will cause TCAM resources waste of

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