PMTU detection method and device

Abstract

The invention provides a PMTU detection method and device, electronic equipment and a medium. The method comprises the following steps: acquiring detection messages and judging whether equal-cost multipath routing is hit or not, wherein the detection messages comprise levels and field intervals; if the equal-cost multipath routing is hit, processing the levels and the field intervals of the detection messages, and obtaining the detection message for each piece of equal-cost multipath routing and the level and the field interval included in the detection message; and sending the corresponding detection message through each piece of equal-cost multipath routing, so that a destination node of the detection message performs recombination according to the level and the field interval included in the received detection message, obtains a recombination result and returns the recombination result to an originating node. According to the invention, detection messages are recombined according to levels and field intervals of the detection messages, PMTU detection of equal-cost multipath routing can be realized, and the accuracy and the comprehensiveness of the PMTU detection are improved.

Description

technical field [0001] The present disclosure relates to the fields of computer technology and communication technology, and in particular, to a PMTU detection method, device, electronic equipment and media. Background technique [0002] At present, when a network device transmits a message, it is necessary to consider the size relationship between the size of the message and the MTU (Maximum Transmission Unit, maximum transmission unit) of the outgoing interface of the message. When the packet length is less than or equal to the MTU of the outgoing interface, it can be sent directly; when the packet length is larger than the MTU of the outgoing interface, it cannot be sent directly on the interface, but needs to be fragmented. [0003] Fragmentation can be performed by the originating node of the message, or by an intermediate transmission node. Fragmented messages need to be reassembled, and the reassembly is generally performed by the destination node of the message. An...

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Problems solved by technology

[0006] 3. If the intermediate device needs to encapsulate the message, for example, various tunneling protocols such as IPSec (Internet Protocol Security, Internet Security Protocol), the available MTU value of the intermediate device will further decrease, which may cause the intermediate device to divide the message. piece

However, the equal-value sharing algorithm may not match the outgoing interface selected by the ICMP packets sent during PMTU detection and the actual traffic packets, which may cause the PMTU value obtained by detection to be greater than the PMTU of the path through which the packets are actually forwarded.

In this case, it will still be negatively affected by packet fragmentation and reassembly

Even if the device can choose the path with the smallest MTU value in the equivalent value for PMTU detection by specifying, it still cannot guarantee the accurate PMTU value detected globally

[0014] For example, a packet hits equal-cost routes 1 and 2, and the equivalent-cost route selected to send the packet is 1, whose outbound interface MTU value is greater than the MTU value of the packet, and another equivalent The MTU is smaller than the MTU value of the packet. Therefore, even if the PMTU value of the path detected this time is the MTU value of the packet, if the packet is forwarded by the equal-cost route 2 next time, the packet will need to be fragmented.

[0015] In the existing technical solutions, due to the possible existence of equivalent routes, the PMTU detected by the probe message is inaccurate, which in turn causes the forwarding path of the subsequent traffic message sent according to the PMTU to be inconsistent with the path of the probe message, resulting in Unnecessary packet fragmentation and reassembly operations

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