README: Add section about capturing authentication messages

This commit is contained in:
Marcel Holtmann 2014-08-10 18:13:35 -07:00
parent 9fbd454c88
commit b66765635f
1 changed files with 18 additions and 0 deletions

18
README
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@ -106,6 +106,24 @@ packets with ARPHRD_NETLINK type. They can be read using iwmon:
At this time iwmon is not able to write PCAP files by itself. This might
change in future versions.
When also the authentication protocol traffic on port 0x888e (ETH_P_PAE)
is needed, then a second capture is required:
tcpdump -i any 'ether proto 0x888e' -w trace-pae.pcap
It is possible to combine these two PCAP files using the mergecap utility
and create a combined trace file:
mergecap -F pcap -w trace.pcap trace-file.pcap trace-pae.pcap
This will create a trace.pcap file that includes the complete picture
of nl80211 netlink traffic and authentication messages. All packets are
merged in chronological order based on timestamps.
Unfortunately it is not possible to instruct tcpdump filtering to do
this in a single capture. Post-processing of the PCAP files is required
at the moment.
Simulating devices
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