Hello,
You need to enter a custom interface name value. First, create a tag and assign base interface to it.
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=13137009899423150694)
Create a new interface with DHCP server:
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=13226679257468069027)
Enter a --Custom-- interface name eth0.X. Replace X with your tag value and press enter:
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=2620691218599614126)
This will create a virtual interface within the device:
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=15086615850339652256)
To test, set the tag for your network interface:
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=12237159430965556084)
The gateway assigns IP from VLAN 192.168.15.0/42 pool:
![](https://community.teltonika-networks.com/?qa=blob&qa_blobid=15380679655425186071)
Best regards,