Configuring Service VLANs

Context

Layer 2 data packets delivered from a VAP to an AP carry the service VLAN IDs.

Since WLANs provide flexible access modes, STAs may connect to the same WLAN at the office entrance or stadium entrance, and then roam to different APs.

If a single VLAN is configured as the service VLAN, IP address resources may become insufficient in areas where many STAs access the WLAN, and IP addresses in the other areas are wasted.
After a VLAN pool is created, add multiple VLANs to the VLAN pool and configure the VLANs as service VLANs. In this way, an SSID can use multiple service VLANs to provide wireless access services. STAs are dynamically assigned to VLANs in the VLAN pool, which reduces the number of STAs in each VLAN and also the size of the broadcast domain. Additionally, IP addresses are evenly allocated, preventing IP address waste.

VLAN assignment algorithms include even and hash.
- When the VLAN assignment algorithm is set to even, service VLANs are assigned to STAs from the VLAN pool based on the order in which STAs go online. Address pools mapping the service VLANs evenly assign IP addresses to STAs. If a STA goes online many times, it obtains different IP addresses.
- When the VLAN assignment algorithm is set to hash, VLANs are assigned to STAs from the VLAN pool based on the harsh result of their MAC addresses. As long as the VLANs in the VLAN pool do not change, the STAs obtain fixed service VLANs. A STA is preferentially assigned the same IP address when going online at different times.

Note the following when adding service VLANs to the VLAN pool:

After a VLAN pool is configured as a service VLAN for wireless users, the VLAN pool cannot be configured as the VLAN pool assigned to users who pass authentication by the RADIUS server.
After a VLAN pool is configured as a service VLAN for wireless users, VLANs in the VLAN pool cannot be deleted. To delete the VLAN pool, cancel the service VLAN configuration of the VLAN pool.
If a VLAN or the VLAN pool to which a VLAN belongs has been configured as a service VLAN for the WLAN network, the VLAN cannot be configured as a super-VLAN. Similarly, if a VLAN has been configured as a super-VLAN, the VLAN or the VLAN pool to which the VLAN belongs cannot be configured as a service VLAN for the WLAN network. In addition, if a VLAN pool has been configured as a service VLAN for a WLAN network, a super-VLAN cannot be added to the VLAN pool.
In scenarios where a dual-stack address pool is configured, a user successfully obtains an IP address if the VLAN pool has assigned an IPv4 or IPv6 address to it. In this case, the VLAN pool will not assign a new VLAN to this user.

Procedure

Run system-view
The system view is displayed.
Configure a VLAN pool.
This step is required when VLANs in a VLAN pool are used as service VLANs.
1. Run the vlan batch { vlan-id1 [ to vlan-id2 ] } &<1-10> command to create VLANs in a batch.
2. Run the vlan pool pool-name command to create a VLAN pool and enter the VLAN pool view.
  By default, no VLAN pool is created on a device.
3. Run the vlan { start-vlan [ to end-vlan ] } &<1-10> command to add VLANs to the VLAN pool.
  By default, no VLAN is available in a VLAN pool.
4. (Optional) Run the assignment { even | hash } command to configure a VLAN assignment algorithm in the VLAN pool.
  By default, the VLAN assignment algorithm is hash in a VLAN pool.
  
  The VLAN assignment algorithm configuration affects only newly connected STAs, but not those that have been connected to the network.
5. Run the quit command to return to the system view.
Run wlan
The WLAN view is displayed.
Run vap-profile name profile-name
The VAP profile view is displayed.
Run service-vlan { vlan-id vlan-id | vlan-pool pool-name }
A service VLAN is configured for a VAP.

By default, VLAN 1 is the service VLAN of a VAP.