HTTP/3 over AnyConnect

[Robturner1]

We are doing some testing with one of our servers to enable HTTP/3(TLSv1.3) and we are seeing this working on the internal LAN and working from an external connection (public internet)

When we are trying to connect whilst connected to our AnyConnect VPN we are only seeing HTTP/2(TLSv1.2)

is this something that is being blocked or is it something that is not supported by the currently AnyConnect client?

ASAv - 9.17

AnyConnect Client - 4.10.04071

[balaji.bandi]

I have not tested, as per one of the session ASA do support TLS 1.3, next test check the Logs while accessing the site, also capture with wireshark, what you see on the server side ?

[Robturner1]

Morning

When I am not connected to the VPN, wireshark is showing the TLSv1.3 and QUIC protocols being used, when on the VPN, all I am seeing is TLSv1.2 from a client perspective

[MHM Cisco World]

Anyconnect use tis 1.3 so there is conflict with server I think.