[CentOS] log outbound port 80 connections

[Ray Van Dolson]

On Tue, Feb 05, 2008 at 09:29:30AM -0800, John R Pierce wrote:
> Tony Schreiner wrote:
>>> assuming you want to log user web browsing traffic, configuring a Squid 
>>> transparent proxy at your network border would be the best way.  its 
>>> logfiles are quite similar to those of a webserver, so you can use a wide 
>>> range of log analysis tools.
>>>
>> To get more specific about what's going on.  My network services have 
>> informed me that the machine is probing other systems at a high rate. An 
>> infection of some sort. And I'm trying to track down what's going on.
>
> ah.  tcpdump -i ethX tcp port 80
>
> (and prepare for a flood of data).
>

If you decide to use tcpdump at all, maybe just limit to SYN packets as
well:

  tcpdump -n -i ethX 'tcp port 80 and tcp[tcpflags] & tcp-syn != 0'

Ray