Structure Analysis of RIP Protocol

In the learning of RIP, we understand its concept, features, and versions. Here we mainly analyze the basic structure of the RIP Protocol. Through our introduction, we believe that you can have a specific understanding of the RIP Protocol grouping format. Similar to the structure of most grouping formats, the routing protocol grouping format is not hard to understand here.

The format of the RIP Protocol.

The grouping formats of ip rip and IP RIP2 are described below.

1. RIP protocol grouping format

Command -- indicates whether the group is a request or a response. The request group requires the router to send all or part of its route table.

A response group can be an active periodic route update or response to a request. A large route table can use multiple RIP groups to transmit information.

Version number -- indicates the RIP version used. This field can notify different versions of incompatibility.

Zero -- unused.

Address Family flag (AFI)-specify the address family used. RIP is designed to carry routing information of different protocols.

Each item has an address family flag to indicate the address type used. The AFI of the IP is 2.

Address -- specify the IP address of the item.

Metric indicates the number of vrouters that have passed through the target process. The valid path value is between 1 and 15, and 16 indicates the inaccessible path.

Note: up to 25 AFI, address, and metric fields can be contained in an ip rip Protocol group.

2. RIP2 group format

The RIP2 specification (RFC1723) allows the RIP group to contain more information and provides a simple authentication mechanism.

Command -- indicates whether the group is a request or a response. The request group requires the router to send all or part of its route table.

A response group can be an active periodic route update or response to a request. A large route table can use multiple RIP groups to transmit information.

Version -- indicates the RIP version used. The value is 2 in the RIP Protocol group that implements RIP2 or performs authentication.

Not used -- the value is 0.

Address Family flag (AFI) -- specifies the address family in use. RIP is designed to carry routing information of different protocols. each item has an address family flag to indicate the address type used. The AFI of the IP is 2.

If the AFI of the first item is 0 xFFFF, the remaining part of the item is the authentication information. Currently, the only authentication type is a simple password.

Route tag-provides a method to distinguish between internal routes learned by RIP) and external Routes learned by other protocols.

IP address -- specify the IP address of this item.

Subnet Mask -- the subnet mask that contains this item. If this field is 0, the subnet mask is not specified.

Next Hop -- specify the IP address of the next hop.

Metric indicates the number of vrouters that have passed through the target process. The valid path value is between 1 and 15, and 16 indicates the inaccessible path.

Note: up to 25 AFI, address, and metric fields can be contained in an ip rip Protocol group. if AFI indicates authentication information, there are only 24 route table entries.