This web site provides info about Wireshark (formerly Ethereal), a network protocol analyzer that enables you to capture and analyze packets from a network.
I'm having a bit of a trouble trying to figure out how to tell which network protocol users HAVE been logging in with. I know how to find this information for currently logged in users :
maximillian.gardner@syccuxfs01:~> who
joseph.blosser pts/0 2012-01-15 14:07 (198.107.160.185)... (5 Replies)
Hi guys,
i want to know about network protocol testing.
1. What is network protocol testing?
2. Whats the role of network protocol tester?
3. Is there good future scope in network protocol testing field?
4. Just give me a example of protocol testing.
5. How it relates to perl or unix?
Thanks... (0 Replies)
I have installed ethereal on solaris 10. however I can execute the ./ethereal using the root account. if tried to execute same from non-root users i am facing the following error.
ethereal: The capture session could not be initiated (/dev/ce: Permission denied).
Please check to make sure... (2 Replies)
by default, a mac syncs its time and date with time.apple.com (located system prefs->Date&Time). Is there a way in unix to change it to another address?
my attempts to use ntpdate and ntpd have failed. (4 Replies)
Hi All;
plz suggest me any perl script to get the ethereal messeges.To be more specific, i need to write a perl script that when an ethereal tool is started and captures any traces, can get that trace......... :) (0 Replies)
Hi to all ....
i must install ethereal-0.8.18-1 on aix system , for do some problems determination about network problems .
I have a .bff file of ethereal but for resolve dependencies i need this two .bff package needed :
freeware.gtk+.rte 1.2.8.0 # Base Level Fileset... (1 Reply)
I have a small program written in C using winsock v1, that uses a unix host to get the time.
I have two machines networked, one windows, the other red hat 9.
The windows machine will request the time off the RH one.
How can I configure red hat to reply to the time request, i.e act as an... (1 Reply)
Hi,
I work with an interface which connects to a Switch company and pulls information from certain sockets. During the night, somehow disconnects and it is difficult to prove if it is the interface or the Switch company responsible. I had the suggestion to install sniffers to do some network... (2 Replies)
One of the users on my network took my aside and showed me a program called ethereal that can sniff out packets on the network. He was able to re-build a packet stream and see pretty clearly what other users where looking at.
I am using a hub. If I use a switch will that stop ability to be... (7 Replies)
MERGECAP(1) The Wireshark Network Analyzer MERGECAP(1)NAME
mergecap - Merges two or more capture files into one
SYNOPSIS
mergecap [ -a ] [ -F <file format> ] [ -h ] [ -s <snaplen> ] [ -T <encapsulation type> ] [ -v ] -w <outfile>|- <infile> [<infile> ...]
DESCRIPTION
Mergecap is a program that combines multiple saved capture files into a single output file specified by the -w argument. Mergecap knows
how to read libpcap capture files, including those of tcpdump, Wireshark, and other tools that write captures in that format.
By default, Mergecap writes the capture file in libpcap format, and writes all of the packets from the input capture files to the output
file.
Mergecap is able to detect, read and write the same capture files that are supported by Wireshark. The input files don't need a specific
filename extension; the file format and an optional gzip compression will be automatically detected. Near the beginning of the DESCRIPTION
section of wireshark(1) or http://www.wireshark.org/docs/man-pages/wireshark.html <http://www.wireshark.org/docs/man-pages/wireshark.html>
is a detailed description of the way Wireshark handles this, which is the same way Mergecap handles this.
Mergecap can write the file in several output formats. The -F flag can be used to specify the format in which to write the capture file,
mergecap -F provides a list of the available output formats.
Packets from the input files are merged in chronological order based on each frame's timestamp, unless the -a flag is specified. Mergecap
assumes that frames within a single capture file are already stored in chronological order. When the -a flag is specified, packets are
copied directly from each input file to the output file, independent of each frame's timestamp.
The output file frame encapsulation type is set to the type of the input files if all input files have the same type. If not all of the
input files have the same frame encapsulation type, the output file type is set to WTAP_ENCAP_PER_PACKET. Note that some capture file
formats, most notably libpcap, do not currently support WTAP_ENCAP_PER_PACKET. This combination will cause the output file creation to
fail.
OPTIONS -a Causes the frame timestamps to be ignored, writing all packets from the first input file followed by all packets from the second input
file. By default, when -a is not specified, the contents of the input files are merged in chronological order based on each frame's
timestamp.
Note: when merging, mergecap assumes that packets within a capture file are already in chronological order.
-F <file format>
Sets the file format of the output capture file. Mergecap can write the file in several formats; mergecap -F provides a list of the
available output formats. The default is to use the file format of the first input file.
-h Prints the version and options and exits.
-s <snaplen>
Sets the snapshot length to use when writing the data. If the -s flag is used to specify a snapshot length, frames in the input file
with more captured data than the specified snapshot length will have only the amount of data specified by the snapshot length written
to the output file. This may be useful if the program that is to read the output file cannot handle packets larger than a certain size
(for example, the versions of snoop in Solaris 2.5.1 and Solaris 2.6 appear to reject Ethernet frames larger than the standard Ethernet
MTU, making them incapable of handling gigabit Ethernet captures if jumbo frames were used).
-T <encapsulation type>
Sets the packet encapsulation type of the output capture file. If the -T flag is used to specify a frame encapsulation type, the
encapsulation type of the output capture file will be forced to the specified type, rather than being the type appropriate to the
encapsulation type of the input capture files.
Note that this merely forces the encapsulation type of the output file to be the specified type; the packet headers of the packets will
not be translated from the encapsulation type of the input capture file to the specified encapsulation type (for example, it will not
translate an Ethernet capture to an FDDI capture if an Ethernet capture is read and '-T fddi' is specified).
-v Causes mergecap to print a number of messages while it's working.
-w <outfile>|-
Sets the output filename. If the name is '-', stdout will be used. This setting is mandatory.
EXAMPLES
To merge two capture files together, 100 seconds apart use:
capinfos -aeS a.pcap b.pcap
(Let's suppose a.pcap starts at 1009932757 and b.pcap ends at 873660281. 1009932757 - 873660281 - 100 = 136272376 seconds.)
editcap -t 136272376 b.pcap b-shifted.pcap
mergecap -w compare.pcap a.pcap b-shifted.pcap
SEE ALSO pcap(3), wireshark(1), tshark(1), dumpcap(1), editcap(1), text2pcap(1), pcap-filter(7) or tcpdump(8) if it doesn't exist.
NOTES
Mergecap is based heavily upon editcap by Richard Sharpe <sharpe[AT]ns.aus.com> and Guy Harris <guy[AT]alum.mit.edu>.
Mergecap is part of the Wireshark distribution. The latest version of Wireshark can be found at <http://www.wireshark.org>.
HTML versions of the Wireshark project man pages are available at: http://www.wireshark.org/docs/man-pages
<http://www.wireshark.org/docs/man-pages>.
AUTHORS
Original Author
-------- ------
Scott Renfro <scott[AT]renfro.org>
Contributors
------------
Bill Guyton <guyton[AT]bguyton.com>
1.8.2 2012-06-05 MERGECAP(1)