Analysis on Application of Route Distribution Function

Application background of the route Distribution Function

The company has a networking project with the branch. Based on the core exchange configurations at both ends, the solution is to use the dynamic routing of the VPN to implement HA and load banlance.

Problem:

Because the VLAN information at both ends is conflicted, I have been busy with how to coordinate and handle VLAN issues. All the static routes used by the peer branch are configured with a VPN gateway. This was a strange phenomenon in the first online test. After the point-to-point configuration was completed, the peer side learned all of my route information, but I couldn't learn the other side's information. What's even more strange is that the Peer learns new conflicting routing information, which affects the peer network. (according to the principle, the level of Static Routing is the highest. people cannot understand it in the field, I have the opportunity to see it again ).

Solution:

This is not the case. Run the static route first and try again. If the problem occurs, you have to find a solution. The two words have to be done. You have an idea in your mind. How can you control the Routes learned by the peer end, (ACL ROUTER-MAP and so on one by one flash), it is best to move out of the CISCO information, the replication of the network, the dawn of [Distribute] Is it.

Test results:

I was always busy at work a few days ago. I was always worried about this problem when I was free. When the weekend is free, simulate it on the simulator.VroIs distribute-list, and the result is as scheduled.

Ps: During the simulation, we also had an episode. For the simulator of the Exchange version, the VLAN Division information of the simulator was not found in the routing, and baidu was later aware of it. The test is completed by switching to the route version.

Show:

 
 

  
  
router eigrp 1  
  
  
network 1.1.1.0 0.0.0.3  
  
  
network 192.168.0.0  
  
  
network 192.168.100.0  
  
  
distribute-list 7 out Serial1/1  
  
  
no auto-summary  
  
  
!  
  
  
ip classless  
  
  
no ip http server  
  
  
!  
  
  
access-list 7 permit 192.168.100.0 0.0.0.255  
  
  
! 
 
 

The new user has finished reporting... Constantly learning ing... At this moment, we will repeat the MD5 of the network.

PS: add the online materials to favorites again

Summary: distribute-list controls information in the route table.

First understand: in will change itself out will change others

I. Distance vector protocol (Rip)

Because routing information is directly transmitted from the distance vector protocol, the routing information of the corresponding protocol is controlled in and out directions of the running Protocol process interface.

Distribute-list in controls the route information in the in direction of the Protocol interface and only changes itself (the route information is changed before the route table is generated) other vrouters are not changed (unless the VBR affects the re-release of other protocols)

Distribute-list out controls the route information in the out direction of the Protocol interface and does not change it by yourself (the route table has been generated). Other routers will change.

Ii. Link Status Protocol Ospf Is-Is

Because the Link Status Protocol transmits LSA (LSU) information, after each router synchronizes LSA (LSU), each router runs the SPF algorithm based on the database information to obtain the route table information. Route information is not directly transmitted between interfaces in and out. However, similar distance vector protocols of LSA may be affected, so the external routes of Class 5 will be changed by distribute-list. If the network (ospf) of a pure Link Status Protocol does not have 5 types of LSA:

Distribute-list out does not work (other routers are not changed), but it works between different processes. For example, R2 (config-router) # distribute-list 1 out ospf 1 (no lab verification)

Distribute-list in does not change the ospf database information, but filters the generated route information.

The application solution of the routing distribution function has been introduced to you. I hope you have gained some insights through the above configuration process.