Method and device for refreshing hardware forwarding table and routing equipment

Abstract

The invention relates to a hardware forwarding table refreshing method, a hardware forwarding table refreshing device and routing equipment. A software copy is set for a hardware forwarding table in a memory of the routing equipment, and a refreshing operation on the hardware forwarding table is realized by the following steps that: a CPU firstly accesses the memory, refreshes the software copy and informs indexes of changed table items to a hardware refreshing unit; and the hardware refreshing unit accesses the software copy in the memory through a DMA mode, and writes the changed table items into the hardware forwarding table item by item according to the indexes. The method and the device can realize quick refreshing of the hardware forwarding table.

Description

technical field [0001] The invention relates to the technical field of communication, in particular to a hardware forwarding table refreshing method, a hardware forwarding table refreshing device and a routing device. Background technique [0002] With the development of network technology, mainstream network equipment, such as medium and high-end switches and most routers, can support large-scale forwarding tables; for example, Chinese patent CN02100458.7 provides a high-speed Route lookup system: through the specially set route lookup coprocessor to receive the route refresh command sent by the routing protocol through the central processing unit (CPU) interface, control SRAM (static memory) and CAM (Content Addressable Memory, content addressable memory) Perform hardware refreshing and storage of routing and forwarding table entries, thereby supporting large-capacity routing and forwarding tables. [0003] However, the refreshing technology of the existing hardware forwa...

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Problems solved by technology

However, as can be seen from the above descriptions of the IPv4 / v6 FTN table and the IPv4 / v6 ACL table, the existing hardware forwarding table refresh technologies all directly operate on the hardware forwarding table stored in the hardware (such as SRAM and CAM), involving a large number of The forwarding entry migration problem caused the table entry refresh progress to be very slow;

[0014] The above-mentioned low refresh efficiency has caused the following problems: although the software forwarding table of the CPU has been updated, the hardware forwarding table stored in the hardware (such as SRAM and CAM) and based on the actual forwarding has not been synchronized in time. The published item did not take effect, causing a security black hole; it is very difficult to overcome this security black hole through software design

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