Problems with racluster
Rafael Barbosa
rrbarbosa at gmail.com
Mon Sep 3 04:46:46 EDT 2012
Hi Carter,
The issue with the direction seems to be solved using clients 3.0.7.1: the
single duplicated ACK from the previous connection is aggregated in the
second connection, and the direction is not reversed.
$> ra -r f1.argus f2.argus
21:09:30.970830 e * tcp 172.31.1.102.61722 ->
172.31.1.100.10500 22 6772 FIN
21:09:30.971095 e tcp 172.31.1.100.10500 ?>
172.31.1.102.61722 1 66 CON
21:11:52.493919 e * tcp 172.31.1.102.61722 ->
172.31.1.100.10500 23 6838 FIN
$> racluster -r f1.argus f2.argus -f ~/config/racluster.conf
StartTime Flgs Proto SrcAddr Sport Dir
DstAddr Dport TotPkts TotBytes State
21:09:30.970830 e * tcp 172.31.1.102.61722 ->
172.31.1.100.10500 22 6772 FIN
21:11:52.493919 e * tcp 172.31.1.102.61722 ->
172.31.1.100.10500 24 6904 FIN
However, if the duplicated packet is aggregated in the second record, why
isn't the 'start time' also set to the time of the duplicated packet? In
any case, would it be possible to aggregate the dup packet in the first
record?
Best regards,
Rafael Barbosa
http://www.ewi.utwente.nl/~barbosarr/
On Sat, Sep 1, 2012 at 6:09 PM, Carter Bullard <carter at qosient.com> wrote:
> Hey Rafael,
> Give this copy a run to see if it doesn't do the right thing for you.
> If so, I'll push the changes to all the aggregators.
> Are you using 3.0.6.2 clients or 3.0.7.1 ?
> Thanks !!!!!!
>
> Carter
>
>
>
> On Aug 30, 2012, at 8:29 AM, Carter Bullard <carter at qosient.com> wrote:
>
> Hey Rafael,
> Your situation should work fine, if not for the racluster() bug.
>
> The only problem is that racluster() gives precedence to the first record,
> not the record with the definitive data, so the fix should be simple, I
> hope. I'll try to fix this today.
>
> Regarding the model, I was just providing an example racluster.conf. The
> status and idle timers are the important part.
>
> Carter
>
>
> On Aug 30, 2012, at 3:55 AM, Rafael Barbosa <rrbarbosa at gmail.com> wrote:
>
> Hi Carter,
>
> I do not care much about the first record, as long as the second record
> keeps its correct direction. As you said, the second record contains the
> 3-way handshake necessary to decide the flow direction.
>
> I am not sure if this is important, but my original example is a little
> more complicated: I have another pcap file with the rest of the TCP
> connection from which the first packet (from the first record in f2.argus)
> belongs. The packet that generates the first record f2.argus is a duplicate
> for the ACK that completes the teardown of this TCP connection. To make
> sure I am clear:
>
> $> ra -r f1.argus
> 21:09:30.970830 e * tcp 172.31.1.102.61722 ->
> 172.31.1.100.10500 22 6772 FIN
> $> ra -r f2.argus
> 21:09:30.971095 e tcp 172.31.1.100.10500 ?>
> 172.31.1.102.61722 1 66 CON
> 21:11:52.493919 e * tcp 172.31.1.102.61722 ->
> 172.31.1.100.10500 23 6838 FIN
> $> racluster -r f1.argus f2.argus -f ~/config/racluster.conf
> 21:09:30.970830 e * tcp 172.31.1.102.61722 ->
> 172.31.1.100.10500 22 6772 FIN
> 21:09:30.971095 e * tcp 172.31.1.100.10500 ->
> 172.31.1.102.61722 24 6904 FIN
>
> I just assumed the bug is in the second file. But if you think is
> necessary I can provide you with the first argus dump as well.
>
> Regarding my racluster.conf, I do not really care about real-time, as I am
> using argus to post-process pcap files (I do not have access to the
> network, just the dumps). But I have a question, why to you suggest to use
> the 5-tuple as a "model" in racluster.conf? Isn't this the default behavior?
>
> And as usual, thanks for the fast reply.
>
> Best regards,
> Rafael Barbosa
> http://www.ewi.utwente.nl/~barbosarr/
>
>
>
> On Wed, Aug 29, 2012 at 8:19 PM, Carter Bullard <carter at qosient.com>wrote:
>
>> Hey Rafael,
>> Yes, I'll have to fix this bug were the second record is erroneously
>> reversed. The fix, however,
>> will end up reversing the first record. The second record saw the
>> connect setup, so it knows
>> the correct direction. The first flow, is just the one packet, without
>> any detail, so the direction
>> is unknown. When you try to merge the two flows together, the bug is
>> that it only looks at the first
>> record for the direction, rather than evaluating both, and choosing the
>> one that is a better choice.
>>
>> Is that cool with your line of thinking?
>>
>> If you're planning on running argus with 300s status intervals, that will
>> eliminate any real-time
>> possibilities. But if you're thinking about letting argus generate
>> shorter lived status records, then
>> run racluster() with a racluster.conf file, where you set a status timer
>> for all flows at 300s:
>>
>> filter="" model="saddr daddr proto sport dport" status=300 idle=300
>>
>> Hopefully this helps !!!!
>>
>> Carter
>>
>> On Aug 29, 2012, at 9:22 AM, Rafael Barbosa <rrbarbosa at gmail.com> wrote:
>>
>> Hi all,
>>
>> I am having some problems with a weird aggregation decision by racluster,
>> which inverts the server/client roles (i.e., the direction field). This
>> what happens:
>>
>> $> argus -r f2 -w f2.argus
>> $> ra -r f2.argus
>> 21:09:30.971095 e tcp 172.31.1.100.10500 ?>
>> 172.31.1.102.61722 1 66 CON
>> 21:11:52.493919 e * tcp 172.31.1.102.61722 ->
>> 172.31.1.100.10500 23 6838 FIN
>> $> racluster -r f2.argus -f racluster.conf
>> 21:09:30.971095 e * tcp 172.31.1.100.10500 ->
>> 172.31.1.102.61722 24 6904 FIN
>> $> cat racluster.conf
>> filter="" status=0 idle=300
>>
>> The pcap from which I generated f2.argus is attached to this message. The
>> 'f2' pcap file is rather peculiar with duplicated frames and is a fragment
>> of a larger capture where TCP ports are re-used in consecutive connections,
>> but it is not a "toy" file, it was captured in a real network environment.
>>
>> My goal is to generate flow records with a 300s timeouts, and label hosts
>> as servers and clients. Any thoughts on why this inversion happens, and how
>> I can work around it?
>>
>> Thanks for the help,
>> Rafael Barbosa
>> http://www.ewi.utwente.nl/~barbosarr/
>>
>> <f2>
>>
>>
>>
>
>
>
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