Method and router equipment for realizing load sharing

Abstract

The invention discloses a method for realizing load sharing. The method includes: acquiring a load sharing strategy and generating a load sharing link table; The load sharing error count value searches the load sharing link table to obtain the next hop and outgoing interface information, and forwards the message according to the next hop in the load sharing link table and the outgoing interface information; according to the load sharing link table The next hop and the outgoing interface information in the forwarding message; the invention also discloses a routing device for realizing load sharing. According to the solution of the present invention, efficient forwarding of messages can be realized.

Description

technical field [0001] The invention relates to the technical field of IP packet forwarding, in particular to a method and routing equipment for realizing load sharing. Background technique [0002] In routers, switches and other devices, when forwarding packets with the same destination IP, the outbound interfaces in the routing table found according to the destination IP are all the same, that is, all traffic passes through the next hop in the routing table And the outgoing interface is sent to the next device. Then, when the traffic exceeds the interface bandwidth or is subject to traffic management, some data will be discarded by the router device, thus affecting the normal business of users. In order to reduce the possibility of data loss, the data traffic of the same destination IP can be allocated to multiple different links according to a certain strategy during forwarding, and finally converged to a common target device, which is load sharing. [0003] There are ge...

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Problems solved by technology

[0003] There are generally two routing strategies for load sharing: the first one is to evenly distribute the traffic of the same destination IP to all load sharing links. This routing strategy is suitable for applications that do not require high traffic order In some cases, the advantage is that the traffic is absolutely balanced, but the disadvantage is that the sequence of packets cannot be guaranteed, such as figure 1 As shown, the packets with the same destination IP to Router B will be evenly distributed to three links and forwarded to Router B. However, because the time taken for forwarding through different links is different, the order of the packets after arriving at Router B may be different. After receiving out-of-sequence packets, the user will send a request to resend the packets, which will reduce the network service quality; the second is to select the link according to the traffic characteristics, and the packets with the same destination IP will be based on the port number and protocol Different types generate flow signatures, and each flow signature corresponds to a load sharing link, thus ensuring that the same service traffic of users goes through the same link, reducing the possibility of packet disorder and improving service quality, but , the same disadvantage is: when a certain type of service traffic occupies more bandwidth, the load sharing effect of the link cannot be reflected, the same as figure 1 As shown, assuming that the same destination IP message to router B is only classified and routed according to the protocol type, it is possible that the User Datagram Protocol (UDP, User Datagram Protocol) message will go through link one, and the Transmission Control Protocol (TCP, Transmission Control Protocol ) packets go to link 2, thus ensuring that packets of the same protocol type select the same link and reducing the possibility of packet disorder

[0004] In the existing load sharing implementation methods, whether it is a uniform routing method based on packets or a routing method based on flow characteristic identification, it is necessary to map the packet sequence number, or random number, or packet flow characteristic identification to the load To share a link, generally use the method of calculating the remainder of the number of links by using the flow feature identifier. For processors without a remainder calculation module, implementing this algorithm in software takes up a lot of instruction lines. For network processors, If a certain algorithm occupies too many command lines in the processing flow of a message, it will cause the forwarding performance of the router device to decrease.

[0005] In addition, if the maximum range of the packet sequence number or random number used is not a multiple of the number of load-sharing links, when using the packet-based uniform routing method, traffic will generate errors and will not be completely evenly distributed to each link. on the road

like figure 1 As shown, when the packet sequence number range is 0-65535 (16Bits counter), the load sharing link is as follows figure 1 For the three outbound interfaces with the same bandwidth shown in the figure, when calculating the routing of the packet, use the sequence number of the packet to calculate the remainder of 3, and the remainder of 0 will be one more than the remainder of 1 or 2. Therefore, select the link There will be one more message for each message, and a certain error will occur after a long time of forwarding; when the range of the sequence number of the message is smaller, the error will be more obvious

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