VLAN technology and applications
1 Broadcast Domain
The broadcast domain refers to the range that receives the same broadcast message. Any device in this range sends a broadcast and all other devices can receive it. By default, all interfaces of the switch belong to the same broadcast domain
2 VLAN Overview
VLAN, Virtual LAN (Virtual LAN)
All interfaces of the switch belong to the same broadcast domain by default. As the number of access devices increases, broadcasts in the network increase, reducing network efficiency. VLANs can be used to divide broadcast domains to avoid this problem.
VLAN splits broadcast domains
Function (advantages) of VLAN:Broadcast control, increased security, improved bandwidth utilization, reduced data transmission delay
VLAN classification based on interface
3 Divide VLAN
Create the following VLAN on the switch, add the port to the specified VLAN according to topology diagram-1 and configure the server IP address to achieve communication with the VLAN host
Create a vlan and add the interface. Since all interfaces are in VLAN1 by default and VLAN1 exists by default, you only need to configure VLAN2 and VLAN3. <Huawei>system-view [Huawei]vlan 2 //Create vlan2, if you want to delete it, you can use undo vlan 2 [Huawei]display vlan //View vlan list [Huawei-vlan2]quit [Huawei]interface ethernet 0/0/3 //Enter interface 3 [Huawei-Ethernet0/0/3]port link-type access //Set the interface type to access link [Huawei-Ethernet0/0/3]port default vlan 2 //Add the interface to vlan2 [Huawei-Ethernet0/0/3]quit [Huawei]interface ethernet 0/0/4 //Enter interface 4 [Huawei-Ethernet0/0/4]port link-type access //Set the interface type to access link [Huawei-Ethernet0/0/4]port default vlan 2 //Add the interface to vlan2 [Huawei-Ethernet0/0/4]quit [Huawei]vlan 3 //Create vlan3 [Huawei-vlan3]quit [Huawei]interface ethernet 0/0/5 //Enter interface 5 [Huawei-Ethernet0/0/5]port link-type access //Set the interface type to access link [Huawei-Ethernet0/0/5]port default vlan 3 //Add the interface to vlan3 [Huawei-Ethernet0/0/5]quit [Huawei]interface ethernet 0/0/6 //Enter interface 6 [Huawei-Ethernet0/0/6]port link-type access //Set the interface type to access link [Huawei-Ethernet0/0/6]port default vlan 3 //Add the interface to vlan3. If you add the wrong vlan, type the correct command again
Multi-switch VLAN division
[Huawei]vlan batch 2 3 //Create vlan in batches. If you want to delete it, you can use undo vlan batch 2 3 [Huawei]port-group 1 //Create (enter) interface group 1 group-member Ethernet 0/0/3 Ethernet 0/0/4 //Add members 3 and 4 to the interface group port link-type access //Set the interface type to access link port default vlan 2 //Add all interfaces in the interface group to vlan2 [Huawei-port-group-1]quit [Huawei]port-group 2 //Create (enter) interface group 2 group-member Ethernet 0/0/5 Ethernet 0/0/6 //Add members 5 and 6 to the interface group port link-type access port default vlan 3 [Huawei-port-group-2]undo group-member Ethernet 0/0/7 //If the interface is added incorrectly, for example, port 7 is accidentally added to interface group 2, you can use this command to delete it. Use the undo command, which is equivalent to Cancel
Two Trunk
1 Trunk principle
VLAN communication between switches
Devices in the same VLAN will be connected to different switches
How to achieve the same VLAN communication between switches?
One link per VLAN?
How to achieve the same VLAN communication between switches?
Using only one link, how is data from multiple VLANs identified?
VLAN ID
The switch tags each data frame destined for other switches with a VLAN tag.
2 Configure trunk relay chain
Implement same-VLAN communication across switches through configuration
Note: The following configuration needs to be completed based on case 2 access access link can carry data of 1 vlan Trunk trunk link can carry data of multiple vlans 1) sw1 configuration [Huawei]interface ethernet 0/0/7 port link-type trunk //Configure as a trunk link port trunk allow-pass vlan all //Release all vlan data 2) sw2 configuration [Huawei]interface ethernet 0/0/7 port link-type trunk //Configure as a trunk link port trunk allow-pass vlan all //Release all vlan data display vlan //Query the vlan list, you can see that in any vlan, there is interface No. 7 If the interface configuration is chaotic and needs to be restored: [Huawei]clear configuration interface Ethernet 0/0/7 //Clear configuration [Huawei]interface ethernet0/0/7 //Enter the interface [Huawei-Ethernet0/0/7]undo shutdown //Open the interface
3 Link Aggregation
Eth-trunk
- Multiple lines are load balanced and bandwidth is increased
- Fault tolerance, when one line fails, the entire network will not be interrupted.
Link aggregation configuration
Use the previous case to configure link aggregation and bundle multiple links (network cards) together to achieve the purpose of increasing reliability and link bandwidth.
Create a link aggregation interface and bundle the physical interface 1) sw1 configuration [Huawei]interface eth-trunk 1 //Create (enter) link aggregation interface No. 1 trunkport Ethernet 0/0/7 0/0/8 //Bundle interfaces 7 and 8 port link-type trunk //Configure as a trunk link port trunk allow-pass vlan all //Release all vlan data 2) sw2 configuration [Huawei]interface eth-trunk 1 //Create (enter) link aggregation interface No. 1 trunkport Ethernet 0/0/7 0/0/8 //Bundle interfaces 7 and 8 port link-type trunk //Configure as a trunk link port trunk allow-pass vlan all //Release all vlan data Use display vlan to see that ports 7 and 8 in the list have disappeared and been replaced by Eth-Trunk1
Three Network Layer Analysis
1 Functions of the network layer
IP address defined
Connect different media types (different ranges of networks, different hardware, different systems)
Selecting the path for data to pass through the network (routing)
2 Network layer protocol
（1）ICMP (Internet Control Message Protocol) Internet Control Message Protocol
Transported via IP datagrams, used to send error and control information
Common ping feedback results
- The connection is established successfully, Reply from target address
- Destination host unreachable, Destination host unreachable
- Request timed out, Request timed out
（2）ARP (Address Resolution Protocol) Address Resolution Protocol
When sending data on the network, the target IP and target mac address are required. However, since only the target IP address is known when sending, and its mac address is not known, ARP can be used to parse the target mac address based on the IP address information to ensure smooth communication. conduct
Four Routing Principles and Configuration
1 Routing Overview
Send packets from one network to another
Routers can choose paths based on routing tables
- Each router maintains a routing table, which is the key for the router to forward data packets.
- Each routing table record indicates: which interface should be used to reach a certain network segment.
2 Routing table
Direct connection routing, configure the IP address of the interface and automatically generate it after turning it on.
Static, default route
- Manually specified by the administrator on the router
Dynamic Routing
- Automatically set by the router through routing protocols based on changes in network topology or traffic
- Suitable for ISP service providers, WAN, and other large networks
3 Static routing
Use the ip route-static command
Specify the destination IP network
Basic format: [Huawei] ip route-static target network ID subnet mask next hop
4 Connect to the Internet using a router
VLAN, Trunk, etc. can be configured on the switch to meet the basic requirements for building a network, but data cannot be transmitted further. For example, different VLANs cannot communicate with each other, so the network layer and related equipment are required.
[Huawei]interface GigabitEthernet 0/0/0 //Enter interface 0 [Huawei-GigabitEthernet0/0/0]ip address 192.168.1.254 24 //Configure ip [Huawei-GigabitEthernet0/0/0]quit [Huawei]interface GigabitEthernet 0/0/1 [Huawei-GigabitEthernet0/0/1]ip address 192.168.2.1 24 <Huawei>display ip interface brief //View all IP configurations of the device [Huawei-GigabitEthernet0/0/1]undo ip address //If the ip configuration is wrong, use this command to delete it
After that, configure the IP and gateway of the two PCs to communicate with each other.
The IP of pc1 is 192.168.1.1 and the gateway is 192.168.1.254
The IP of pc2 is 192.168.2.2 and the gateway is 192.168.2.1
A gateway is a way for a device to connect to another network, allowing a router (a device with routing functions) to
display ip routing-table | include /24 //View routing table
5 Configure static routing
Add routers and PCs to transform the previous topology into the following state. The ultimate goal is to interconnect the entire network.
First configure all IP addresses of the device as before second router [Huawei]interface GigabitEthernet 0/0/0 //Enter interface 0 [Huawei-GigabitEthernet0/0/0]ip address 192.168.2.2 24 //Configure ip [Huawei-GigabitEthernet0/0/0]quit [Huawei]interface GigabitEthernet 0/0/1 //Enter interface 0 [Huawei-GigabitEthernet0/0/1]ip address 192.168.4.254 24 //Configure ip [Huawei-GigabitEthernet0/0/1]quit [Huawei]interface GigabitEthernet 0/0/2 [Huawei-GigabitEthernet0/0/2]ip address 192.168.3.254 24 <Huawei>display ip interface brief //View all IP configurations of the device pc configuration: The gateway of 192.168.4.1 is 4.254 The gateway of 192.168.3.1 is 3.254 Configure static routing on the first router: [Huawei]ip route-static 192.168.3.0 24 192.168.2.2 //Add a static route, you can go to network segment 3.0, mask 24, next hop 2.2 [Huawei]undo ip route-static 192.168.3.0 24 192.168.2.2 //If the route configuration is wrong, delete it [Huawei]ip route-static 192.168.4.0 24 192.168.2.2 //Add a static route, you can go to network segment 4.0, mask 24, next hop 2.2 Configure static routing on the second router: [Huawei]ip route-static 192.168.1.0 24 192.168.2.1 //To add a static route, you can go to network segment 1.0, mask 24, next hop 2.1 display ip routing-table | include /24 //View routing table