HTTP/2 Packet Analysis with Wireshark

Published: 2022-08-26
Last Updated: 2022-08-27 02:06:54 UTC
by Guy Bruneau (Version: 1)
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I have been getting these queries in my honeypot logs since end of December 2021 and decided to a diary on some of these packets using some basic analysis with Wireshark. Handlers have published a few diaries over the years [1][2][3] regarding this protocol. These packets are from[4] which is a site that provides internet discovery and inventory like Shodan. In my logs, the activity looked like this:


20220822-014547: data 
PRI * HTTP/2.0


Before I update my Wireshark filter, select HTTP2 and add port TCP/3389, the data looked like some kind of HTTP traffic. The payload appears to indicate it is HTTP/2.0 and the protocol need to be updated with port TCP/3389 in order to parse the packet properly.


Lets update the configuration preferences to view the activity as HTTP/2. To change the preferences select Edit, Preferences, Protocols, HTTP2 and add port 3389 and apply the change:



According to RFC 7540, "All frames begin with a fixed 9-octet header followed by a variable- length payload."[6]



After applying the http2 change to Wireshark, we can now see HTTP2 header corretly decoded as per RFC7540:



This last picture shows the HTTP2 payload decoded as per RFC 7540 above picture with a Stream length of 24 and its 31 bits (all 0) identifier:




Guy Bruneau IPSS Inc.
My Handler Page
Twitter: GuyBruneau
gbruneau at isc dot sans dot edu

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