Application Scenario
In Figure 5-6, a company has multiple departments using different switches. To improve service security, the company adds different departments to different VLANs, but IP addresses of the company are limited.
The requirements are as follows:
- All departments want to access the Internet.
- Department 1 and department 2 need to communicate with each other.
- Department 3 and department 4 need to communicate with each other.
VLAN aggregation can be deployed to meet the preceding requirements. Deploy super-VLAN 2 and super-VLAN 3 on the switch, and add sub-VLAN 21 and sub-VLAN 22 to super-VLAN 2 and sub-VLAN 31 and sub-VLAN 32 to super-VLAN 3. After IP addresses are assigned to super-VLAN 2 and super-VLAN 3 on the switch, users in department 1 and department 2 can access the Internet using the IP address of super-VLAN 2, and users in department 3 and department 4 can access the Internet using the IP address of super-VLAN 3.
Therefore, VLAN aggregation allows all departments to access the Internet access and conserves IP addresses.
CTo allow communication between department 1 and 2 and departments 3 and 4, configure proxy ARP on the switch in super-VLAN 2 and super-VLAN 3.