issue with reuse of existing host tap interface for a port

[Amaresh Parida]

Hi,

As I understood for each port sonic creates corresponding host tap interface in the Kernel. For Example, when sonic boot with Ethernet0 is the phy port it creates corresponding tap interface in the kernel name Ethernet 0.

Considering this if my fast path( my fast path is a soft path) creates a tap interface to send slow path packet to sonic by creating a tap interface with the same name Ethernet0(To send packet via kernel tcp/ip stack), shouldn’t sonic while booting see the tap for Ethernet0 already present and what ever packet the fast path is sending on Ethernet0, sonic should be able to read (Example creating an ip interface on Ethernet 0 and enable ospf on top of that to get ospf packet from fast path to sonic).

 The observation is if we give the same TAP name sonic see the interface is present and remove from the list of portInitDone and I see for those port the state_db also not getting updated.

 Is the understanding correct? Please let me know is there any other way to send packet to sonic host interface other than this approach. Shouldn’t sonic overwrite or fill all the DB again for existing TAP interface like how it does for new TAP interface?

Thanks,

Amaresh