- Written by Manuel Mendez
- Posted on September 30, 2019
- Updated on November 5, 2025
- 12074 Views
Subinterfaces divide a single ethernet or port channel interface into multiple logical L3 interfaces based on the 802.1q tag (VLAN ID) of incoming traffic. Subinterfaces are commonly used in the L2/L3 boundary device, but they can also be used to isolate traffic with 802.1q tags between L3 peers by assigning each subinterface to a different VRF. L3 subinterface shaping + VRF is also supported.