Static and floating routes

Catalog

Preface

One . How routers work

Two . The formation of routing table

3、 ... and . Static routing

Four . Default route

5、 ... and . Floating route

6、 ... and . Router forwarding packet encapsulation process

7、 ... and . Static routing configuration

  summary

---

Preface

Router works in OSI The network layer of the reference model , Its important role is to choose the best path for the transmission of data packets , Has reached its destination .

One . How routers work

Forward data according to routing table

1.PC1 I want to send data to PC2, Because it is not the same network segment , therefore pc1 It can only be sent to the router of this network segment a gateway
2. The router receives a packet , View the source and destination of the packet IP, Looking at the routing table , The data from b The interface of the route is sent , Until arrival pc2 On the contrary, take the data from a The interface sends out , Until arrival pc1.

Two . The formation of routing table

Direct connection network segment
To configure ip Address , port UP state , Form a direct route
Non direct network segment
Through static and dynamic routing protocols

3、 ... and . Static routing

Manually configured by the administrator , Is one-way
Lack of flexibility

Four . Default route

When the router cannot find the routing entry of the target network in the routing table , The router forwards the request to the default routing interface

5、 ... and . Floating route

Two or more links form a floating route

Same destination address , Different next hop addresses , The priority of the next hop is low

6、 ... and . Router forwarding packet encapsulation process

1、 Source IP192.168.10.10  Purpose IP192.168.20.10
Source MAC 11-11 Purpose MAC 22-22
First ARP Broadcast precipitation g/0/0/0 Of MAC Address , For the first time
2、 Unpack first , The purpose of viewing packets IP, Query routing table , Determine the forwarding path , Give the router 2
3、 First ARP Broadcast resolution router 2 g0/0/0 Of MAC Address , Carry out the second packaging
Source IP 192.168.10.10 Purpose IP 192.168.20.10
Source MAC 33-33 Purpose MAC 44-44
4、 Unpack first , The purpose of viewing packets IP Connect the network segment directly for yourself , adopt E0/0/1 Forward to PC2
5、 First ARP The broadcast parses PC2 Of MAC Address , Carry out the third packaging
Source IP 192.168.1.2 Purpose IP 192.168.2.2
Source MAC 55-55 Purpose MAC 66-66

7、 ... and . Static routing configuration

R1 To configure

undo t m
system-view 
user-interface console 0
idle-timeout 0
q
int g0/0/0
ip add 192.168.10.1 24
int g0/0/2
ip add 192.168.50.2 24
int g0/0/1
ip add 192.168.30.3 24
q
ip route-static 192.168.60.0 24 192.168.50.1
ip route-static 192.168.20.0 24 192.168.60.2
ip route-static 192.168.40.0 24 192.168.30.1 preference 70
ip route-static 192.168.60.0 24 192.168.40.2 preference 70
ip route-static 192.168.20.0 24 192.168.60.2 preference 70

R2 To configure

system-view 
user-interface console 0   
idle-timeout 0
q
int g0/0/0
ip add 192.168.30.1 24
int g0/0/1
ip add 192.168.40.1 24
q
ip route-static 192.168.10.0 24 192.168.30.3 preference 70  
ip route-static 192.168.60.0 24 192.168.40.2 preference 70   
ip route-static 192.168.20.0 24 192.168.60.2 preference 70

R3 To configure

undo t m
system-view  
user-interface console 0
idle-timeout 0
q
int g0/0/0
ip add 192.168.40.2 24
int g0/0/2
ip add 192.168.50.1 24
int g0/0/1
ip add 192.168.60.1 24
q  
ip route-static 192.168.30.0 24 192.168.40.1 preference 70
ip route-static 192.168.10.0 24 192.168.50.2
ip route-static 192.168.10.0 24 192.168.30.3 preference 70
ip route-static 192.168.20.0 24 192.168.60.2

R4 To configure

system-view 
user-interface console 0
idle-timeout 0
q
int g0/0/0
ip add 192.168.60.2 24
int g0/0/1
ip add 192.168.20.1 24
q
ip route-static 192.168.50.0 24 192.168.60.1
ip route-static 192.168.10.0 24 192.168.50.2
ip route-static 192.168.40.0 24 192.168.60.1 preference 70
ip route-static 192.168.30.0 24 192.168.40.1 preference 70  
ip route-static 192.168.10.0 24 192.168.30.3 preference 70

test result

 

  summary

Static configuration should be bidirectional

Floating priority setting

Packets are routed ,MAC Address reseal