I have Wireshark installed in two laptops, one injecting custom packets into the network and another sniffing these injected packets. When I transmit the packets using the fist machine (Macbook Pro using Broadcom BCM 4331 interface card), I am able to see these packets in Wireshark with all the various fields such as SSI, Noise etc.
But the Wireshark installed on the other machine (Dell Latitude E6410 using the Intel Corporation Centrino Ultimate-N 6300 interface card) shows the radio-tap header to be of length 18 only, and is missing parameters like Noise and timestamp.
Could anyone explain why this is happening? Is it because different wireless drivers treat radio-tap in a different way? If so, how can I get the missing parameters like background noise?
I have attached screen-shots of wireshark running on the two machines.
Some wirless network interaces do not make the additional information available. The details are dependent on the OS involved, the Wireshark version, and the mode you have set up in the interface. There is a good discussion at http://wiki.wireshark.org/CaptureSetup/WLAN#Link-Layer_.28Radio.29_packet_headers which should get you started.
answered 18 Jun '12, 16:38