capture http headers

[admin]

sudo tcpdump -s 1024 -l -A port 80 | tee dump.txt

-s Snarf snaplen bytes of data from each packet rather than the default of 65535 bytes.
Packets truncated because of a limited snapshot are indicated in the output with ``[|proto]'', where proto is the name of the protocol level at which the truncation has occurred.
Note that taking larger snapshots both increases the amount of time it takes to process packets and, effectively, decreases the amount of packet buffering.
This may cause packets to be lost.
You should limit snaplen to the smallest number that will capture the protocol information you're interested in.
Setting snaplen to 0 sets it to the default of 65535, for backwards compatibility with recent older versions of tcpdump.

-A Print each packet (minus its link level header) in ASCII. Handy for capturing web pages.
-l Make stdout line buffered. Useful if you want to see the data while capturing it. E.g., tcpdump -l | tee dat