* Note: This article is intended for the majority of users to learn. Some of them will mention some professional Internet terms or abbreviations. If you do not understand the network, you can learn and explore it together. If you have any questions, you can add QQ or YY. (QQ: 914560310, YY: 283755973) "//" is not a command output or description.
RIP Protocol Introduction: Dynamic Routing Protocols include distance vector routing protocol and link state routing protocol, and RIP is the most widely used distance micro vector routing protocol. RIP is designed for a small network environment, because such protocols are routing learning and route updates, which will generate a large amount of traffic and occupy excessive network bandwidth, the larger the network environment, the larger the traffic, so RIP is only applicable to small network environments.
RIP protocols are divided into version 1 and version 2. They all have the following features:
- Is the distance vector routing protocol,
- Use the number of hops as the metric value (the number of network devices that span, and a network device becomes a hop)
- The default route update cycle is 130 s (RIP sends the RIP Protocol packet every s by default to update the route table ),
- The Management Distance (AD) is 120. (The smaller the AD value, the faster the router selects the nearest value based on the AD value .)
- Update triggering is supported (triggering an update means that if you remove a vro, you will find that this is a feature of Dynamic Routing)
- The maximum number of hops is 150 (the maximum number can span 150 network devices)
- Supports equivalent paths. The default value is 4, and the maximum value is 6.
- Use the UDP520 short blank to update the route.
The difference between r1_1 and r1_2 is:
R00001 r00002
No subnet information is carried during route update. subnet information is carried during route update.
No authentication is provided. The inscription is MD5 authentication.
VLSM and CIDR are not supported. VLSM and CIDR are not supported.
Broadcast update and Multicast (222.0.0.9)
Classless Routing Protocol
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Next we will use a small experiment to better learn and understand the RIP Protocol:
* Configure the IP address and loopback port first.
After completing the configuration before the experiment, we will configure router R1 and use it as an example:
R1 # configure terminal // enter the Configuration Mode
Enter configuration commands, one per line. End with CNTL/Z.
R1 (config) # router rip // start the RIP Protocol
R1 (config-router) # version 1 // configure RIP version 1
R1 (config-router) # network 1.0.0.0 // advertise the network, which means to tell others the network they are connected
R1 (config-router) # network 192.168.12.0
R1 (config-router) # exit
R1 (config )#
Then, all other routers are operated according to the R1 configuration. Configure the RIP1 version and then advertise the network to which you are connected.
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R1 # show ip route // view the route table.
Codes: C-connected, S-static, I-IGRP, R-RIP, M-mobile, B-BGP
D-OSPF, EX-VPN external, O-OSPF, IA-OSPF inter area
N1-ospf nssa external type 1, N2-ospf nssa external type 2
E1-OSPF external type 1, E2-OSPF external type 2, E-EGP
I-IS, L1-IS level-1, L2-IS level-2, ia-IS inter area
*-Candidate default, U-per-user static route, o-ODR
P-periodic downloaded static route
Gateway of last resort is not set
1.0.0.0/24 is subnetted, 1 subnets
C 1.1.1.0 is directly connected, Loopback0
R 4.0.0.0/8 [120/3] via 192.168.12.2, 00:00:02, Serial0/3/0
C 192.168.12.0/24 is directly connected, Serial0/3/0
R 192.168.23.0/24 [120/1] via 192.168.12.2, 00:00:02, Serial0/3/0
R 192.168.34.0/24 [120/2] via 192.168.12.2, 00:00:02, Serial0/3/0
R1 #
The above output indicates that router R1 has learned the three-step RIP route,
R 4.0.0.0/8 [120/3] via 192.168.12.2, 00:00:02, Serial0/3/0"Is:
1. R: This route information is learned through the RIP routing protocol.
2. 4.0.0.0/8: indicates the target network.
3. [120/3]: The default Management Distance of the RIP Protocol is 120. The measured value from R1 to 4.0.0.0/8 is 3 hops,
4. 192.168.12.2: Next Hop address
5, 00; 00; 02: 28 s from the next update (the default RIP Update time is 30 s)
6. Serial0/3/0: interface of the router that receives the route entry
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R1 # show ip protocols // view the configuration and statistics of the IP routing protocol.
Routing Protocol is "rip" // The router runs the RIP Protocol.
Sending updates every 30 seconds, next due in 24 seconds // The update cycle is 30 s, and there are still 24 s from the next update
Invalid after 180 seconds, hold down 180, flushed after 240 // if the route entry has not received the update in S, it is marked as an Invalid route. If an update is not received within S, the route entry is deleted from the routing table.
[Note] the entries marked as invalid routes are similar to the following: "R 4.0.0.0/8 is possibly down, routing via 192.168.12.2, Serial0/0/0"
There are many ways to enable the route entry to enter an invalid cycle, such as adding an ACL to the interface that rejects the receipt of the UDP520 port, or setting the port as a passive port. We will not introduce it here.
Outgoing update filter list for all interfaces is not set // No filtering table is set in the outbound direction,
Incoming update filter list for all interfaces is not set // No filter table is set in the Inbound direction,
Redistributing: rip
Default version control: send version 1, receive 1 // The Default version control is version 1.
Interface Send Recv Triggered RIP Key-chain
Loopback0 1 1
Serial0/3/0 1 1
Automatic network summarization is in effect
Maximum path: 4
Routing for Networks:
1.0.0.0
192.168.12.0
Passive Interface (s ):
Routing Information Sources:
Gateway Distance Last Update
192.168.12.2 120 00:00:07
Distance: (default is 120)
R1 #
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The Update Time of the RIP Protocol, the time when the update cannot be received, the time when the update is marked as an invalid route entry, and the time when the update cannot be received, the entry is deleted. These three time administrators can manually modify them. Let's talk about them:
R1 (config) # route rip
R1 (config-router) # version 1
R1 (config-router) # timers basic? // Follow? Check what commands can be entered later,
<0-4294967295> Interval between updates // update the timer and set the Update Time
R1 (config-router) # timers basic 100? // We set it to s and then see what commands can be entered later
<1-4294967295> Invalid // Invalid timer, and the set time to mark as Invalid route entries
R1 (config-router) # timers basic 100 200? // We set it to 200 s.
<0-4294967295> Holddown // sets the time when the timer is resisted.
R1 (config-router) # timers basic 100 200 300? // Set to 300 s
<1-4294967295> Flush // set how long it will take to delete this route entry before the update is received.
R1 (config-router) # timers basic 100 200 300 400? // Set to 400 s
<Cr> // indicates that no command can be entered later,
R1 (config-router) # timers basic 100 200 300
R1 (config-router )#
We can see that there is an additional resistance timer (also called the prepared timer) in the middle ), we can also set the actual time when the timer is resisted. I will not introduce the timer too much here (if you are interested, you can check it online or contact me, I still have a bit of information about this). If you set it, the time to resist the timer is generally a little shorter than that of the invalid timer.
* Note: The default Update Time of the RIP Protocol is 30 s. If an update of a route entry is received when it is not 30 s, it starts timing again from 0.
R1 # clear ip route // ("*" indicates that all RIP Protocol tables and ip addresses are cleared)
R1 (config) # no route rip // disable the RIP Protocol
