RIP (Route information Protocol) Routing Information Protocol

2. RIP: A distance vector protocol, the distance is distance, the number of hops to represent, vector is vectors, interface to represent. Based on the Bellham-ford (distance vector) algorithm, belongs to the IGP (Internal Gateway Protocol) class.

4. RIP is divided into the class routing protocol (RIPV1) and the No-class routing Protocol (RIPV2).

6. RIPv1 and RIPv2 the same point:

   1. are all using hops as measures (metric), their maximum hop count is 15 hops, that is, they can connect up to the number of routers is 15 units.

   2. Supports auto-summarization, but RIPV2 supports manual summarization, while V1 is not.

   3. Up to 6 load balancers are supported, but 4 by default.

   4. In the network, only one subnet mask can be used, and it is fixed-length.

8. RIPv1 and RIPv2 different points:

   1. RIPV2 is an enhanced version of RIPV1 called a hybrid protocol.

   2. RIPV1 does not support triggering updates.

   3. RIPV1 sends an update using a broadcast address of 255.255.255.255, and RIPv2 uses an update address of 224.0.0.9 is the multicast address.

   4. RIPV2 supports variable eldest-son netmask (VLSM), while RIPV1 is not supported.

   5. RIPv2 supports interface validation, while RIPV1 is not supported.

   6. When using two different versions, the RIPV1 can receive the routing information of the RIPV2, otherwise it is not.
      

10. RIP two packet transfer information: Update and request. The router is approximately every 30 seconds or so (there is a random time, avoiding too much routing information on the link) to update once, using the UDP520 port.

    The distance between distances is used as the scale of the network. Each router sends a message to the neighboring router, with an internal distance (1) for each path, which is the number of hops.

12. a very important point of knowledge : the way to prevent loops, the loop problem is also a common problem in distance vector routing protocol, because the DV protocol can not form a network topology.
    

    1. Maximum hop count 15: More than 15 hops are unreachable and can prevent loop problems.

    2. Horizontal split: Routing information obtained from an adjacent router is no longer sent back to this neighbor. You can also use the no IP Split-horizon interface subcommand to turn off the ability to split horizontally.

    3. Poison reversal: This routing information metric is set to infinity, greater than or equal to 16 and sent back. The function is to notify other routers that the route is unreachable.

    4. Hold down: Use the Hold-downtimer timer to avoid routing table flips.

    5. Flash UPDATE: Trigger the update to speed up the aggregation time, when the measure (metric) of the path changes, the route sends the update information immediately, regardless of whether it arrives at regular update time.

Note: Horizontal segmentation and toxicity routing, reverse routing can not be used at the same time!

This article is from the "Batman" blog, make sure to keep this source http://5740675.blog.51cto.com/5730675/1588952

RIP (Route information Protocol) Routing Information Protocol