Huge thanks to our Platinum Members Endace and LiveAction,
and our Silver Member Veeam, for supporting the Wireshark Foundation and project.

Wireshark-users: Re: [Wireshark-users] Force Wireshark to decode part of Data as another protocol

From: Guy Harris <guy@xxxxxxxxxxxx>
Date: Tue, 22 Jul 2014 00:20:49 -0700
On Jul 21, 2014, at 11:15 PM, Rayne <hjazz6@xxxxxxxxx> wrote:

> I have some traffic samples where the Layer 2 is PPP and the next protocol field value is 0x0281, which indicates MPLS Unicast. There are 4 bytes following this PPP header before I see the IP header. However, Wireshark has decoded everything after the PPP header as Data.

What version of Wireshark are you using?

> I can't choose the "Decode As" option in this case, as it is greyed out. How can I force Wireshark to decode the 4 bytes after the PPP header as something else, say MPLS in this case?

Use the latest version of Wireshark, which appears to support dissecting packets with a PPP protocol value of 0x0281 as MPLS-over-PPP?