I have a single packet capture (acquired via tcpdump) that contains flow records between an exporter and a collector.
I want to determine throughput across a given interface using the bytes (octets) field in the v9 record. I have filtered down to the network that I want like so:
tshark -r input.pcap -Y "ip.src == X.X.X.X" -F pcap -w filtered.pcap
I further filtered to the interface that I needed like so:
tshark -r filtered.pcap -Y "cflow.inputint == Y" -F pcap -w filtered2.pcap
I'm lost after that. Is there a better tool to aggregate across the flows to get throughput?
Any help would be greatly appreciated!
You may try to print netflow fields and then process the results.
For example:
tshark -T fields -e cflow.version -e cflow.srcaddr -e cflow.dstaddr -e cflow.octets -e cflow.timedelta -e cflow.abstimestart
Field names are visible in wireshark status bar when you select packet details.
Better option:
install or compile https://github.com/phaag/nfdump with --enable-readpcap flag.
process your pcap nfcapd -f <path to your pcap file> -l <path to output directory> -T all
count statistics nfdump -o extended -r <path to output directory>
Related
I am trying to get tshark to show the payload of packages in clear text and I am failing in that. Which makes me really sad.
tshark -r pcap -T fiels -e data (or data.text) gives blank results.
tshark -r pcap -T fiels -e tcp.payload gives hex results.
So the question is how do I get tshark to show the tcp.payload als text (ascii).
I would like to know that is there any option in Wireshark to capture packets in the streaming network dynamically. Since I need to capture packets with out doing the export each time and packets capture automatically in a CSV file without exporting it periodically. Thanks.
You should be able to use tshark to achieve this. For example, suppose you want to capture the frame number and source and destination IP addresses of each packet (to keep the example simple), you could use:
tshark -i foo -T fields -E separator=, -E quote=d -E header=y -Y ip -e frame.number -e ip.src -i ip.dst > output.csv
You can specify as many fields as you want using the -e option
I have a bunch of pcap files that I got with tcpdump. I need to search through all of them for specific keywords and record which files contain these strings. Is there a way to automate the search for these keywords using a tcpdump command perhaps?
Probably the most generic solution using tshark would be to run something like:
tshark -r file.pcap -Y "frame contains foo"
... where foo is the string you're searching for. Refer to the wireshark-filter man page for more information on filtering using the contains and other operators, such as the matches operator which supports Perl compatible regular expressions.
Using that command, the output you'll see will be a 1-line summary of each packet matching the filter. You could tailor the output using a number of methods, but for example, suppose you only wanted to know the frame number of the matching packet, you could run:
tshark -r file.pcap -Y "frame contains foo" -T fields -e frame.number
Refer to the tshark man page for more information on the -T and -e options, as well as other options which may be of use to you.
There is more powerful version of tcpdump, tshark (it is the command line tool from wireshark package). You could use tshark -T fields|pdml|ps|psml|text to dump packets in format you like, and just grep it. tshark could read tcpdump dumps.
In my office firewall I use a command like this:
$ sudo tcpdump -v -s 1500 -i eth0 port 25 | grep 'smtp: S'
to monitor LAN clients sending mail (I need to early detect any possible spammer bot from some client, we have very looooose security policies, here... :-().
So far, so good: I have a continuous output as soon any client sends an email.
But, if I add some filter to get a cleaner output, something like this:
$ sudo tcpdump -v -s 1500 -i eth0 port 25 | grep 'smtp: S' | perl -pe 's/(.*?\)) (.*?)\.\d+ \>(.*)/$2/'
(here I intend to get only source ip/name), I do not get any output until tcpdump output is more than (bash?) buffer size... (or at least I suppose so...).
Nothing changes using 'sed' instead of 'perl'...
Any hint to get a continuous output of filtered data?
Put stdbuf before the first command:
sudo stdbuf -o0 tcpdump ...
But, if I add some filter to get a cleaner output, something like
this:
Use the --line-buffered option for grep:
--line-buffered
Use line buffering on output. This can cause a performance
penalty.
try maybe a sed --unbuffered (or -u sometimes like on AIX) to have a stram version (not waiting the EOF)
I'm analyzing VoIP calls on my network
For now i'm using a generated .pcap file, but later i'll be listening for this at real time.
I'm using tshark, and i can filter some important data pretty easily from the .pcap (like "source ip address and port", "destination ip addr and Port", payload pckt lost, Max Delta(ms),Max Jitter(ms),Mean Jitter(ms)) with
tshark -r myfile -q -z rtp,streams
What i want to know is: how can i get the sip addrs of a call? (client and server)
I can retrieve some sip addrs (only client) by filtering all sip INVITE like this:
tshark -r myFile -R "sip.Request-Line contains INVITE"
But i can't get the address of the server.
To clarify a bit, my idea was to get this "statistic" in tshark, like wireshark gives me when i access "Telephony>VoIP Calls" (the same way that tshark -r myfile -q -z rtp,streamsreturns me statistics just like wireshark's Telephony>RTP>Show All Streams), is there a way to do this? If not with "statistics" (-z) how can i create a filter (-R) to do something similar of the "VoIPCall" function of wireshark
I'm using tshark as i want to work with this data, and not just analyze it on my screen
Thanks
try:
tshark -r myFile -R "sip.CSeq.method eq INVITE"
That will filter for the request sent from the client and the corresponding reply from the server.
I was in a similar situation and ended up going through tshark man pages.
Command: tshark -r input_file.pcap -q -z sip,stat
Explanation:
-r <infile> : Read packet data from infile
-q : When reading a capture file, don't print packet information; this is useful if you're using a -z option to calculate statistics and don't want the packet information printed, just the statistics.
-z <statistics> : Get TShark to collect various types of statistics and display the result after finishing reading the capture file.
You can additionally add filters to the filtering as well, so for example you want to summarize all packets which had only SIP 480 Status Code, you can do so by:
tshark -r input_file.pcap -q -z sip,stat,sip.Status-Code==480
-z sip,stat[,filter] : This option will activate a counter for SIP messages. You will get the number of occurrences of each SIP Method and of each SIP Status-Code
In case you want multiple filters, you can add them one by one
tshark -r input_file.pcap -q -z sip,stat,sip.Status-Code==480 -z sip,stat,sip.Status-Code==500
If you want to summarize by sip address, you can filter by that:
tshark -r input_file.pcap -q -z sip,stat,sip.to.host==sip-to-host.com
Refer:
TShark Man Page: https://www.wireshark.org/docs/man-pages/tshark.html
SIP Filters: https://www.wireshark.org/docs/dfref/s/sip.html