Donald Becker wrote:
On Sat, 10 Nov 2001, Carl-Johan Bostorp wrote:
I want to turn off the CRC check on ethernet frames and pass every
packet up to the kernel.
Why?
I have an eepro100, so I mailed Intel about
it and asked for specs. The reply I got was that the kernel may
actually rely on the NIC doing this check.
So, what's the deal? What effects will there be if the NIC starts
passing everything up to the kernel?
The network stack will interpret arbitrarily corrupted packets as valid
data. Very Bad Things might happen, and you'll not know what occurred or
why.
I doubt that anything would crash because the protocols should already
be hardened against any kind of malicious packet that might come along.
Could you mess up a NIC/Driver with a corrupt packet??
The higher layers like TCP and UDP have their own checksums, so should catch
most bad packets there... (UDP may ignore it's checksum, btw)...
Ben
Donald Becker becker@xxxxxxxxx
Scyld Computing Corporation http://www.scyld.com
410 Severn Ave. Suite 210 Second Generation Beowulf Clusters
Annapolis MD 21403 410-990-9993
--
Ben Greear <greearb@xxxxxxxxxxxxxxx> <Ben_Greear AT excite.com>
President of Candela Technologies Inc http://www.candelatech.com
ScryMUD: http://scry.wanfear.com http://scry.wanfear.com/~greear
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