[Tutor] Reading eth0 With Python

Null Pointer nullpointer at heartoftn.net
Sat Nov 15 17:21:35 EST 2003

On Saturday 15 November 2003 16:53, you wrote:

> Python's device access is normally provided with C programs that
> are managed through a Python interface.  Python is usually too
> slow to directly handle data from a fast device.  Even a C
> program like tcpdump has difficulty keeping up with a busy
> network connection.

I suspected that.

> Your best bet is probably to use tcpdump (or the equivalent) to
> store the packets and use python to analyze the data.
> Are you trying to communicate with or manage a device that
> doesn't support TCP/IP (or some other higher-level protocol)?

Actually, I'm trying to determine when packets are flowing into and 
out of eth0, __except__ for the UDP status packets originating from 
my ISDN-TA/Hub/Router, which arrive every ten seconds.  To do that, 
I need to examine the packets for sending host/port information, 

To put it another way, I want to be able to react to any outbound 
packet and any inbound packet that isn't coming from my 

I do have a script running monitoring the UDP status packets on port 
2071, but I also need to know when data comes in destined for any 
other port, and when any outbound packets occur.

I've considered piping the output of tcpdump into a Python script, 
but I was hoping for a cleaner solution.

Did I mention I am new to Linux and Python.  Nothing like jumping in 
the deep end.  {:^)>

N. P.

> Null Pointer wrote:
> > Anyone know if it is possible to read Linux's eth0 device using
> > Python?

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