Using tap0 with Tcpreplay

This thread on the Wireshark mailing list brought up the issue of not being able to use Tcpreplay with the loopback interface on FreeBSD, e.g.:

orr:/root# tcpreplay -i lo0 /data/lpc/1.lpc
sending out lo0 
processing file: /data/lpc/1.lpc
Unable to send packet: Address family not supported by protocol family

Here is an alternative: use tap0.

orr:/root# ifconfig tap0
ifconfig: interface tap0 does not exist
orr:/root# dd if=/dev/tap0 of=/dev/null bs=1500 &
[1] 9468
orr:/root# ifconfig tap0 up
orr:/root# ifconfig tap0
tap0: flags=8843 mtu 1500
        inet6 fe80::2bd:1dff:fe2d:4d00%tap0 prefixlen 64 scopeid 0x5 
        ether 00:bd:1d:2d:4d:00
        Opened by PID 9468
orr:/root# tcpreplay -i tap0 /data/lpc/1.lpc
sending out tap0 
processing file: /data/lpc/1.lpc
^C
Actual: 71 packets (6860 bytes) sent in 6.15 seconds
Rated: 1115.0 bps, 0.01 Mbps/sec, 11.54 pps

In a second window, sniff with Tcpdump or whatever program you want:

orr:/root# tcpdump -n -i tap0 -s 1515
tcpdump: WARNING: tap0: no IPv4 address assigned
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on tap0, link-type EN10MB (Ethernet), capture size 1515 bytes
10:25:16.211443 00:0d:28:6c:f5:4f > 01:00:0c:cc:cc:cd sap aa ui/C
10:25:17.567563 IP 192.168.2.5.2882 > 10.20.2.19.22:
 P 1293772727:1293772779(52) ack 478395919 win 64444

I discussed this in my first book and in my network security monitoring class.

Comments

Netfortius said…
Wow! That was fast and comprehensive - thank you, Richard.

Interestingly enough, that does not seem to work on my BSD "flavor" (which is at the basis of MacOSX):

pwrbk:~/scm$ sudo dd if=/dev/tap0 of=/dev/null bs=1500 &
[1] 3398
pwrbk:~/scm$ dd: /dev/tap0: No such file or directory

[1]+ Exit 1 sudo dd if=/dev/tap0 of=/dev/null bs=1500

... thus, consequently:

pwrbk:~/remote-mac scm$ ifconfig tap0 up
ifconfig: interface tap0 does not exist

Do you have a tap0 in your BSD /dev ?

Thanks again,
Stefan
11:13 AM
Richard Bejtlich said…
Hi,

MacOS X is not a BSD "flavor." Mac OS X uses BSD userland tools. The kernel is Mach-based.
11:27 AM
Netfortius said…
... just following up on my own comment ;) Should have googled harder before posting :(

This may work - I will give it a shot right now:

http://www-user.rhrk.uni-kl.de/~nissler/tuntap/

Thanks again, Richard!
Stefan
11:29 AM
Anonymous said…
thanks, it work from my BSD
but how to adding the device imto permanent device
so if my computer reboot not to write the command first
3:01 AM
Post a Comment

Popular posts from this blog

Zeek in Action Videos

Image
This is a quick note to point blog readers to my Zeek in Action YouTube video series for the Zeek network security monitoring project .  Each video addresses a topic that I think might be of interest to people trying to understand their network using Zeek and adjacent tools and approaches, like Suricata, Wireshark, and so on.  I am especially pleased with Video 6 on monitoring wireless networks . It took me several weeks to research material for this video. I had to buy new hardware and experiment with a Linux distro that I had not used before -- Parrot .  Please like and subscribe, and let me know if there is a topic you think might make a good video.
Read more

MITRE ATT&CK Tactics Are Not Tactics

Image
Just what are "tactics"? Introduction MITRE ATT&CK  is a great resource, but something about it has bothered me since I first heard about it several years ago. It's a minor point, but I wanted to document it in case it confuses anyone else. The MITRE ATT&CK Design and Philosophy document from March 2020 says the following: At a high-level, ATT&CK is a behavioral model that consists of the following core components: • Tactics, denoting short-term, tactical adversary goals during an attack; • Techniques, describing the means by which adversaries achieve tactical goals; • Sub-techniques, describing more specific means by which adversaries achieve tactical goals at a lower level than techniques; and • Documented adversary usage of techniques, their procedures, and other metadata. My concern is with MITRE's definition of "tactics" as "short-term, tactical adversary goals during an attack," which is oddly recursive. The key word in the tacti...
Read more

New Book! The Best of TaoSecurity Blog, Volume 4

Image
  I've completed the TaoSecurity Blog book series . The new book is  The Best of TaoSecurity Blog, Volume 4: Beyond the Blog with Articles, Testimony, and Scholarship .  It's available now for Kindle , and I'm working on the print edition.  I'm running a 50% off promo on Volumes 1-3 on Kindle through midnight 20 April. Take advantage before the prices go back up. I described the new title thus: Go beyond TaoSecurity Blog with this new volume from author Richard Bejtlich. In the first three volumes of the series, Mr. Bejtlich selected and republished the very best entries from 18 years of writing and over 18 million blog views, along with commentaries and additional material.  In this title, Mr. Bejtlich collects material that has not been published elsewhere, including articles that are no longer available or are stored in assorted digital or physical archives. Volume 4 offers early white papers that Mr. Bejtlich wrote as a network defender, either for technica...
Read more