Couple things...
Craig Merchant
cmerchant at responsys.com
Fri Aug 9 23:34:54 EDT 2013
Hey, Carter... So, I sent your email to the NetOps team. Apparently the duplicate packet problem is well known when you use VLANs as the source of traffic for a SPAN port:
http://blogs.cisco.com/security/span-packet-duplication-problem-and-solution/
I searched over the last 30 million of our flow data events (from racluster) looking for TCP flags with "M" in it. Not a one. So, I can't explain why you saw that in the tcpdump file I sent you, but it doesn't appear to be a pervasive problem.
We're going to contact our reps at Gigamon and see whether their products' flow dedup features might help.
If Argus is seeing duplicate flows, shouldn't it see duplicate SYN and SYN/ACKs? And if so, shouldn't it be able to figure out the direction? I'm still trying to figure out if the problem is a sampling issue with a really busy SPAN port or if it's something else...
We're going to try dropping half the VLANs to reduce the traffic volume and see if that has any impact.
Thanks.
Craig
From: Carter Bullard [mailto:carter at qosient.com]
Sent: Thursday, August 08, 2013 11:00 AM
To: Craig Merchant
Cc: Argus (argus-info at lists.andrew.cmu.edu)
Subject: Re: [ARGUS] Couple things...
Hey Craig,
I've been looking at one of your pcap files, and you've go a lot of weird
stuff going on in your network. You, like a few on the list, have an
observation domain that sees many packets twice. While some say
these are " duplicates ", they are distinct packets on the wire, and seeing
them twice is really an artifact of either how your spanning the packets,
or how you've set up your network.
Possibly you are spanning multiple interfaces to the same argus , and
the packet traverses both of them ?? Or the packet actually traverses
the same physical link twice, but in different overlays or VPNs ???
Argus can be configured to make these mulitple flows distinct, rather than
having the packets aggregated into a single 5-tuple flow record. You can
do that by adding the mac addresses to the flow key, or the VLAN tags
to to the flow key.
I can suggest that you add the LAYER_2 information to argus's flow keys,
to see if you don't get a bit better data. In your argus.conf file:
ARGUS_FLOW_KEY="CLASSIC_5_TUPLE+LAYER_2"
You will need to check the output, so that you can see what is going on.
Post processing of these flows, especially aggregation, will need to account
for the ethernet addresses (by adding the smac and dmac to the aggregation
keys), with calls such as:
racluster -m smac dmac saddr daddr proto sport dport
when you want to do default aggregation.
Here is a sample of one of your pings, between two of your hosts, with the old and new flow key definitions.
I've modified the network and ethernet addresses to protect the innocent.
Standard default 5-tuple flow key
ra -r argus.10*old.out -s stime dur flgs smac dmac proto saddr dir daddr spkts dpkts state - icmp
StartTime Dur Flgs SrcMac DstMac Proto SrcAddr Dir DstAddr SrcPkts DstPkts State
20:00:22.187940 0.005851 M 00:30:48:aa:bb:cc 00:1e:f7:xx:yy:zz icmp 10.30.80.41 <-> 10.20.2.26 1 2 ECO
Standard default 5-tuple flow key with layer 2 identifiers added
ra -r argus.10*new.out -s stime dur flgs smac dmac proto saddr dir daddr spkts dpkts state - icmp
StartTime Dur Flgs SrcMac DstMac Proto SrcAddr Dir DstAddr SrcPkts DstPkts State
20:00:22.187940 0.005851 e 00:30:48:aa:bb:cc 00:1e:f7:xx:yy:zz icmp 10.30.80.41 <-> 10.20.2.26 1 1 ECO
20:00:22.193790 0.000000 e 00:1e:f7:xx:yy:zz d4:8c:b5:cc:dd:ee icmp 10.30.80.41 <- 10.20.2.26 0 1 ECR
As you can see argus, with just the standard 5-tuple flow key, thinks there are 3 packets in the
ping volley, one ping request and 2 ping replys. With the LAYER_2 id's added to the flow key,
we see that one of the echo reply's was also transmitted to another ethernet address ???
The 'M' in the flgs field of the 5-tuple flow record, indicates that there were 'M'ultiple mac addresses
seen for the bi-directional flow. You don't see that in the new flow key strategy.
I don't see a trend, but you do have a lot of asymmetry in how the packets are duplicated.
Take a look at this new flow data, print out the smac and dmac, and see if you can figure it out.
Hope all is most excellent,
Carter
On Aug 8, 2013, at 10:23 AM, Carter Bullard <carter at qosient.com<mailto:carter at qosient.com>> wrote:
Done some testing with your argus.conf file.
Can't find any argus faults using it with your packet files,
on my machines, but there is one issue with the configuration.
Your ARGUS_MONITOR_ID is inappropriate. You only get 32-bits
for a source id, so the max string you can use is 4 characters
long. We'll cut it to 4 chars, so I don't think that this
will cause problems, but it is incorrect.
Carter
On Aug 7, 2013, at 1:40 PM, Craig Merchant <cmerchant at responsys.com<mailto:cmerchant at responsys.com>> wrote:
That worked! Thanks, David. Not sure what in my argus.conf could be causing the problem. Here it is if you're curious:
ARGUS_FLOW_TYPE="Bidirectional"
ARGUS_FLOW_KEY="CLASSIC_5_TUPLE"
ARGUS_DAEMON=no
ARGUS_MONITOR_ID="ids01-dc1"
ARGUS_ACCESS_PORT=561
ARGUS_BIND_IP="10.10.10.10"
ARGUS_INTERFACE=dnacluster:10 at 28
ARGUS_GO_PROMISCUOUS=no
ARGUS_SET_PID=yes
ARGUS_PID_PATH="/var/run"
ARGUS_FLOW_STATUS_INTERVAL=5
ARGUS_IP_TIMEOUT=900
ARGUS_TCP_TIMEOUT=1800
ARGUS_GENERATE_RESPONSE_TIME_DATA=yes
ARGUS_GENERATE_APPBYTE_METRIC=yes
ARGUS_GENERATE_TCP_PERF_METRIC=yes
ARGUS_GENERATE_BIDIRECTIONAL_TIMESTAMPS=yes
ARGUS_CAPTURE_DATA_LEN=10
ARGUS_SELF_SYNCHRONIZE=yes
ARGUS_KEYSTROKE="yes"
From: David Edelman [mailto:dedelman at iname.com<http://iname.com/>]
Sent: Tuesday, August 06, 2013 8:42 PM
To: Craig Merchant; Carter Bullard
Cc: Argus (argus-info at lists.andrew.cmu.edu<mailto:argus-info at lists.andrew.cmu.edu>)
Subject: Re: [ARGUS] Couple things...
Craig,
Just in case you are running into something odd in the argus.conf file, I suggest that you add -X as the very first argument to the invocation of argus. I suggest something very simple like:
# /usr/local/bin/argus -X -r somefile.pcap -w /tmp/somefile.argus
If that works (and /tmp is almost always a good place to write the output because it avoids permission problems) then use recount() on the /tmp/somefile.argus to make sure that everything is as expected and let us know what happened.
--Dave
From: Craig Merchant <cmerchant at responsys.com<mailto:cmerchant at responsys.com>>
Date: Tuesday, August 6, 2013 11:28 PM
To: Carter Bullard <carter at qosient.com<mailto:carter at qosient.com>>
Cc: Argus <argus-info at lists.andrew.cmu.edu<mailto:argus-info at lists.andrew.cmu.edu>>
Subject: Re: [ARGUS] Couple things...
I don't know what to tell you. If you want me to run that trace tool and send you the output, let me know where to get it and I'll figure it out.
Did you take a look at the pcap file to see if there were a lot of missing SYN/SYNACK packets?
Thanks.
Craig
From: Carter Bullard [mailto:carter at qosient.com]
Sent: Tuesday, August 06, 2013 10:02 AM
To: Craig Merchant
Cc: Argus (argus-info at lists.andrew.cmu.edu<mailto:argus-info at lists.andrew.cmu.edu>)
Subject: Re: [ARGUS] Couple things...
Hey Craig,
I'm not having any problems reading your tcpdump.pcap file
with my version of argus, so I can't reproduce a fault.
% thoth:Data carter$ argus -r tcpdump*pcap -w - | racount
racount records total_pkts src_pkts dst_pkts total_bytes src_bytes dst_bytes
sum 402665 9999999 5205934 4794065 4795152829 2664296730 2130856099
Is there a specific feature or command line option that generates
your problem?
Carter
On Aug 3, 2013, at 2:23 PM, Carter Bullard <carter at qosient.com<mailto:carter at qosient.com>> wrote:
OK, with the pcap we'll figure it out.
So the ssh keystroke algorithm is round trip sensitive, and its tuned for the enterprise border viewing, but there are a lot of knobs that can be turned. The real trick is having, again, a packet file of a session so we can see what the algorithm is doing.
Grab a few and we can go over it packet for packet.
Carter
Carter Bullard, QoSient, LLC
150 E. 57th Street Suite 12D
New York, New York 10022
+1 212 588-9133 Phone
+1 212 588-9134 Fax
On Aug 2, 2013, at 3:06 PM, Craig Merchant <cmerchant at responsys.com<mailto:cmerchant at responsys.com>> wrote:
I don't know what to tell you, Carter. The version of 3.0.7.4 that I'm running has the same MD5 sum as the latest in qosient.com/dev<http://qosient.com/dev>...
I've uploaded the pcap file I'm trying to convert to your FTP server.
I've attached the debug file, but after further testing I think it's an algorithm configuration issue. I've tried testing normal and reverse keystroke detection between hosts that were in the same data center and dnstroke and snstroke always show up as "0,0" or ",," (the latter happens more when there are directional issues). But if I watch a host that I ssh into over the VPN from my home connection, Argus detects keystrokes.
I've tried reading through the academic paper you guys published on the keystroke detection and it's beyond me. If it works for a slower network connection and not a faster network connection (or maybe I should say lower/higher latency connection), which configuration options should I experiment with to find the right balance?
Thanks.
Craig
From: Carter Bullard [mailto:carter at qosient.com]
Sent: Friday, August 02, 2013 8:37 AM
To: Craig Merchant
Cc: Argus (argus-info at lists.andrew.cmu.edu<mailto:argus-info at lists.andrew.cmu.edu>)
Subject: Re: [ARGUS] Couple things...
Hey Craig,
Was in Calif all last week, and just now catching up.
I really think the argus crashing issue is fixed. At least
it works with all data that has been uploaded. But if you have
packet data that is blowing argus up, can you send ???
There is a possibility that you may not have the most recent
version of argus-3.0.7.4. I sometimes put up new software
without changing the number, like if I make a mistake and
put up the wrong version. So, there could be a race condition.
Check the md5 or date times, or just grab again, if there is
any doubt.
You have to turn on keystroke detection, so, don't comment out
the ARGUS_KEYSTROKE="yes" line. The CONF line you can comment
out.
To troubleshoot the keystroke algorithm, with argus running, but
not as a daemon, you can send a USR1 signal to it,
# kill -USR1 argus.pid
and it will print out stats that include the keystroke algorithm
configuration, if its turned on. When you send a USR1 signal to
argus, you increment the Debug flag setting for all of argus, and
so you should start getting debug messages, if the debug facility
is compiled in. Send another USR1 and you'll increase the debug
information. Most of the per packet keystroke debugging is at
debug level 5.
Send a USR2 signal to argus ( # kill -USR2 argus.pid ) to turn
debug reporting off.
Carter
On Aug 1, 2013, at 7:02 PM, Craig Merchant <cmerchant at responsys.com<mailto:cmerchant at responsys.com>> wrote:
Hey, Carter...
I just wanted to check in and see if you anything else from me on the labeling issue or argus crashing when trying to convert a pcap file. Let me know...
I'm also having some issues with keystroke detection with the latest release. The following command used to work in my testing:
/usr/local/bin/ra -S 10.10.10.10:561 -n -u -c "," -s "+0dnstroke,+1snstroke" - host 10.1.1.1 and host 10.1.1.2
I tried both a normal and reverse SSH session between the two hosts and neither one registered keyboard strokes of varying speeds and intensity.
All I've done is commented out the defaults in argus.conf:
ARGUS_KEYSTROKE="yes"
ARGUS_KEYSTROKE_CONF="GPC_MAX=4"
I performed pretty much the same testing a couple months ago and got plenty of flows where keystrokes were detected. Please let me know what you'd recommend for troubleshooting that.
Thanks.
Craig
<debug.zip>
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