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Herbert Haas
Guest
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 Posted:
Wed Oct 26, 2005 4:20 pm Post subject:
Using Ethernet cards to create arbitrary frames? |
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Hi experts, hackers.
Does anybody know if Ethernet NICs can be misused to create
arbitrary frames?
As far as I know, cheap NICs don't create the frame
headers by themselves rather it's the job of the SW-drivers.
I would like to do some experiments in basic data communications...
Thanks for help!
Herbert |
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William P.N. Smith
Guest
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| Posted:
Thu Oct 27, 2005 6:02 am Post subject:
Re: Using Ethernet cards to create arbitrary frames? |
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Herbert Haas <haas@removethis.astro.removethat.univie.ac.at> wrote:
| Quote: | Does anybody know if Ethernet NICs can be misused to create
arbitrary frames?
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IIRC, you can build about anything you want with the packet driver
interface. I wrote some code in a previous life to saturate a 10BaseT
network using some old DOS machines, but of course it was on a
separate test LAN. |
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Herbert Haas
Guest
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| Posted:
Thu Oct 27, 2005 2:45 pm Post subject:
Re: Using Ethernet cards to create arbitrary frames? |
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Am Wed, 26 Oct 2005 21:02:57 -0400 schrieb William P. N. Smith:
| Quote: | Herbert Haas <haas@removethis.astro.removethat.univie.ac.at> wrote:
Does anybody know if Ethernet NICs can be misused to create
arbitrary frames?
IIRC, you can build about anything you want with the packet driver
interface. I wrote some code in a previous life to saturate a 10BaseT
network using some old DOS machines, but of course it was on a
separate test LAN.
|
Is it also possible to create non-Ethernet headers?
For example 2-byte address fields, etc...
Thanks
Herbert |
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Manfred Kwiatkowski
Guest
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| Posted:
Thu Oct 27, 2005 4:20 pm Post subject:
Re: Using Ethernet cards to create arbitrary frames? |
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In article <pan.2005.10.27.09.45.04.799875@removethis.astro.removethat.univie.ac.at>,
Herbert Haas <haas@removethis.astro.removethat.univie.ac.at> writes:
| Quote: | Am Wed, 26 Oct 2005 21:02:57 -0400 schrieb William P. N. Smith:
Herbert Haas <haas@removethis.astro.removethat.univie.ac.at> wrote:
Does anybody know if Ethernet NICs can be misused to create
arbitrary frames?
IIRC, you can build about anything you want with the packet driver
interface. I wrote some code in a previous life to saturate a 10BaseT
network using some old DOS machines, but of course it was on a
separate test LAN.
Is it also possible to create non-Ethernet headers?
For example 2-byte address fields, etc...
|
Yes. It is the standard procedure for a driver to assemble the
whole frame in software. The NIC sends whatever there is and does
not care for dest, source or type fields.
Manfred Kwiatkowski kwiatkowski@zrz.tu-berlin.de |
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glen herrmannsfeldt
Guest
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| Posted:
Fri Oct 28, 2005 8:20 am Post subject:
Re: Using Ethernet cards to create arbitrary frames? |
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Manfred Kwiatkowski wrote:
(snip)
| Quote: | Is it also possible to create non-Ethernet headers?
For example 2-byte address fields, etc...
Yes. It is the standard procedure for a driver to assemble the
whole frame in software. The NIC sends whatever there is and does
not care for dest, source or type fields.
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Not to mention, if I remember right, that ethernet includes
a version with 16 bit addresses.
-- glen |
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Rich Seifert
Guest
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| Posted:
Fri Oct 28, 2005 4:20 pm Post subject:
Re: Using Ethernet cards to create arbitrary frames? |
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In article <6f6dnRAsbdkkMPzeRVn-rA@comcast.com>,
glen herrmannsfeldt <gah@ugcs.caltech.edu> wrote:
| Quote: |
Not to mention, if I remember right, that ethernet includes
a version with 16 bit addresses.
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Two-byte addresses are no longer part of the standard; the "feature" was
removed in 1997 (and was never commercially implemented anyway).
--
Rich Seifert Networks and Communications Consulting
21885 Bear Creek Way
(408) 395-5700 Los Gatos, CA 95033
(408) 228-0803 FAX
Send replies to: usenet at richseifert dot com |
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William P.N. Smith
Guest
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| Posted:
Fri Oct 28, 2005 4:20 pm Post subject:
Re: Using Ethernet cards to create arbitrary frames? |
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Herbert Haas <haas@removethis.astro.removethat.univie.ac.at> wrote:
| Quote: | Is it also possible to create non-Ethernet headers?
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Probably, though I don't recall the details. Look up the
documentation on the packet interface, it shold all be there.
BTW, if you start spewing non-ethernet stuff onto the cable, you'd
have a very good chance that it's not going anywhere, as 'broken'
frames (bad checksum, etc) aren't going anywhere, and probably
(hopefully) won't propagate through switches... |
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