VLAN (Virtual Local Area Network) is a technology that can modify the broadcasting domain. A LAN can be divided into several VLANs logically, and only the hosts in the same VLAN can communicate with each other.
LAG (Link Aggregation Group) is a technology that can aggregate multiple physical ports into a logical interface, increasing link bandwidth and providing backup ports to enhance the connection reliability.
Sometimes, we may encounter the application that needs to use these two technologies at the same time; here is a configuration example.
Network Topology:
Network Requirement:
- Users need to improve the bandwidth and redundancy of the link between the switches.
- Hosts in different departments cannot communicate with each other; all hosts can access the internet.
- Both department A and department B can access the internet.
Configuration Scheme:
- Create static LAG1 and LAG2 on switch A, and create static LAG for switch B and switch C respectively.
- Create VLAN 10 and VLAN 20 for department A and department B respectively.
- Create VLAN 30 for the internet, and add the hosts in department A and department B to VLAN 30.
- Configure PVIDs for ports. With correct PVID settings, both department A and department B can access the internet, but cannot communicate with each other.
LAG Configurations on Switch A, Switch B, and Switch C:
|
|
LAG1 |
LAG2 |
|
Switch A |
Port 1,2 |
Port 3,4 |
|
Switch B |
Port 3,4 |
|
|
Switch C |
Port 1,2 |
|
VLAN Configurations on Switch A:
|
|
VLAN 10 |
VLAN 20 |
VLAN 30 |
|
Switch A |
LAG1, port 5 |
LAG2, port 5 |
LAG1, LAG2, Port 5 |
Egress Rule and PVID settings for Switch A:
|
Switch |
Switch A |
||
|
Port |
LAG1 |
LAG2 |
5 |
|
Egress Rule |
Untagged |
Untagged |
Untagged |
|
PVID |
10 |
20 |
30 |
Configurations on Switch A:
Step 1
Go to L2 Features > Switching > LAG > Static LAG, select Group ID as LAG1, select Port 1 and Port 2, click Apply; choose then Group ID as LAG2, and select Port 3 and Port 4, click Apply.
Then verify the LAGs on the LAG Table page.
Step 2
Go to L2 Features > VLAN > 802.1Q VLAN > VLAN Config, create VLAN 10, VLAN 20 and VLAN 30; add Untagged port LAG1 to VLAN 10; add Untagged port LAG2 to VLAN 20; add Untagged port LAG1, LAG2, and port5 to VLAN 30.
Note: When adding ports to VLAN 30, as VLAN 30 including LAG ports and general port, please click UNIT 1 to select general port 5 and then click LAGS to select LAG port 1and LAG port 2.
Then verify the VLANs on VLAN Config page.
Step 3
Go to L2 Features > VLAN > 802.1Q VLAN > Port Config, set the PVID value as 10, 20, 30 for LAG 1, port 2 and port 3 respectively.
Click LAGS in Port Config page and then set the PVID value as 10, 20 for LAG1 and LAG2.
Click UNIT1 in Port Config page and then set the PVID value as 30 for port 5.
Configurations on Switch B:
Only one step, go to L2 Features > Switching > LAG > Static LAG, select Group ID as LAG1, select Port 3 and Port 4, click Apply.
Configurations on Switch C:
Only one step, go to L2 Features > Switching > LAG > Static LAG, select Group ID as LAG1, select Port 1 and Port 2, click Apply.
