Extensions of the packet format in the RIP Protocol

In order to better handle the refresh of the route on the dial-up network, the packet format is improved and expanded according to the RFC/1581/15822091/2092 standard. The packet modification mainly supports three new packet grouping types, which are marked in the packet command field:
9 --------- Update Request modification Request
10 ------- Update Response modify Response
11 -------- Update Acknowledge modification confirmation

The Version field refers to the Version number of each packet, rather than the Version number of RIP, which is mainly based on backward compatibility. Here it must be 1.

Adding a Flush domain is a consideration for the timeliness of routing. If a response packet is sent after receiving the request, it indicates that the sender has never been reachable. If the information of the route to another vro is retained in the sink, the route information may be outdated and need to be updated. To update route information in a vro more quickly. Add a Flush domain to the message. When the vro receives a modified packet with the Flush value, set the original route in the routing database to "temporary route" for timeout processing. When the Flash domain is set to 1, and when it is not set to 0, the message is invalid if other values are taken.

The Sequence number is a tag of packets. It is used to identify the validation packets of each packet, but is only useful to the sender. For the sender, the Sequence number cannot have the same value. to modify the Sequence number of a message, 65535 is generally used as an incremental method of the cycle. The Sequence number value of the confirmed message is the response value corresponding to the modified message. After receiving the confirmation message, the router can confirm that the corresponding modification message has been received according to the Sequence number value.

Related Articles]

• RIP Message format

• Rip technology Overview

• RIP Distance Vector Algorithm