Hi Adam��

> Port 0 flows usually result from fragmented IP datagrams.

why?

We consider traffic destined to port 0 as OS detection. If IP packet
is fragmented, both IP header & TCP/UDP header are copied to new
packets generated.

Looking at his flow-print result, I think there must be some hosts
affacting by virus which keep detecting other hosts' OS and try to
attack at port TCP/445.




> On 2/2/05 12:21 PM, "Dustin" <[EMAIL PROTECTED]> wrote:

>> Hello,
>>  
>> This may have been discussed, but I don't find any results in the archives.
>>  
>> We are troubleshooting some performance issues, have Cisco routers, and just
>> started using flow-tools to capture data.  I've issued flowstat with the
>> following args:
>>  
>> flow-stat -f5 -p -S2
>>  
>> # port      flows                 octets                packets
>> #
>> 0           425                   68968722              51238
>> 445         10886                 51125320              372789
>> 1494        710                   26667144              524757
>> 31889       1800                  21081243              50199
>> 3905        101                   20985596              19102
>> 
>> As you can see, most of the traffic is generated with lower number of 
>> sessions
>> & packets, but w/ higher amount of data.  We would like to know exactly what
>> this traffic is, why is the majority of traffic lumped into "port 0"?
>>  
>> TIA,
>>  
>> Dustin
>>  
>>  
>> _______________________________________________
>> Flow-tools mailing list
>> [EMAIL PROTECTED]
>> http://mailman.splintered.net/mailman/listinfo/flow-tools





-- 
 -- -- 
Regards


Jing Shen

******************************************
* The sunshine of lifetime is made up of *
* little beams which is bright all the   *
* time.                                  *
******************************************


_______________________________________________
Flow-tools mailing list
[EMAIL PROTECTED]
http://mailman.splintered.net/mailman/listinfo/flow-tools

Reply via email to