NVIDIA Docs Hub Homepage NVIDIA Networking BlueField DPUs / SuperNICs & DOCA DOCA Documentation v3.1.0 Core Update Q-in-Q Tunneling

Q-in-Q Tunneling

Q-in-Q tunneling (hardware-accelerated 802.1ad VLAN) enables the creation of a Layer 2 Ethernet connection between two servers. It allows segregation of different VLAN traffic on a link or bundling multiple VLANs into a single VLAN. This is achieved by adding a service VLAN tag before the user’s existing 802.1Q VLAN tags.

Info

For details on Q-in-Q support in virtualized environments (SR-IOV), refer to "Q-in-Q Encapsulation per VF in Linux".

To enable device support for accelerated 802.1ad VLAN:

Turn on the new ethtool private flag phv-bit (disabled by default).
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```
            
            $ ethtool --set-priv-flags eth1 phv-bit on 
        
```
Enabling this flag sets the phv_en port capability.
Change the interface device features by turning on the ethtool device feature tx-vlan-stag-hw-insert (disabled by default).
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```
            
            $ ethtool -K eth1 tx-vlan-stag-hw-insert on 
        
```
Once the private flag and the ethtool device feature are set, the device will be ready for 802.1ad VLAN acceleration.

Note

The phv-bit private flag setting is available for the PF only. The VF can use the VLAN acceleration by setting the tx-vlan-stag-hw-insert parameter only if the private flag phv-bit is enabled by the PF. If the PF enables/disables the phv-bit flag after the VF driver is up, the configuration will take place only after the VF driver is restarted.