How to change the Internal VLAN ID?

Every single interface on the firewall is separated by using VLANs internally. By default, it starts at 2. In SonicOS 7, the default vlan id starts  at 3968.

If you are configuring/using VLAN sub-interfaces on the switch directly connected to the firewall using the same Internal VLAN ID, it might cause unexpected issues.

From firmware version 6.5.3.x onwards, we can now configure the internal VLAN so that they do not overlap with other VLANs connected/configured on the firewall.

Resolution for SonicOS 7.X

This release includes significant user interface changes and many new features that are different from the SonicOS 6.5 and earlier firmware. The below resolution is for customers using SonicOS 7.X firmware.

To change the internal VLAN ID:

1. Click Network on top menu
2. Navigate to Firewall | Advanced 
3. Change the Starting vlan ID under Internal VLAN section 
4. Click Accept
    

   
   

   

NOTE: For the configured internal VLAN to take effect, you must restart the firewall. When you configure the internal VLAN, a RESTART button appears on the MANAGE I Security Configuration | Firewall Settings | Advanced Settings page.

Resolution for SonicOS 6.5

This release includes significant user interface changes and many new features that are different from the SonicOS 6.2 and earlier firmware. The below resolution is for customers using SonicOS 6.5 firmware.

To change the internal VLAN ID:

1. Navigate to MANAGE | Security Configuration | Firewall Settings | Advanced Settings.
2. Scroll to the Internal VLAN section.
   
3. Enter the VLAN ID in the Starting VLAN ID field. The default ID is 2.
4. Click ACCEPT.

For convenience, a link to the MANAGE I Security Configuration | Advanced Settings page has been added to the MANAGE I System Setup | Switching | VLAN Trunking page.

Also,  you can only select the first VLAN number(starting VLAN ID). It assigns that VLAN to the first interface i.e., X0 and keeps incrementing it by 1 for all subsequent interfaces. We cannot assign VLANs to each of the interfaces separately.