need help with tun device network setup, not tap

[calvin2021y]

The document said: Currently firecracker supports only TUN/TAP network backend with no multi queue support.

The example only provide tap example, and I can not find tun device example.

I need to use tun device(layer 3), not tap (layer 2).

any suggestions?

[bchalios]

Hi @calvin2021y. Thanks for getting in touch. Firecracker does not support tun devices, at the moment. We only handle L2 devices.

[calvin2021y]

is tun device doable ?

[bchalios]

virtio-net is a L2 device, hence we tap instead of tun. I guess we could do tun but this would need us to process the frame in Firecracker before passing it over to the tun device. I would expect that to be slower than what the kernel is able to do. Would you mind me asking what is your use-case, in other words, why tap device doesn't work for you?