Re: TOE brain dump

At 05:12 PM 6/08/2003, Andre Hedrick wrote:

Do be sure to check that your data payload is correct.
Everyone knows that a router/gateway/switch with a sticky bit in its
memory will recompute the net crc16 checksum insure it pass the to the nic
regardless.  It is amazing how much data can be corrupted by a network
environment via all the NFS/NBD/etc wantabie storage products out there.

Andre, you are wrong.

firstly, do you REALLY think that most router(s)/switch(es) out there 
recompute IP checksums because they did a IP TTL decrement when routing an 
IP packet or NAT IP addresses?

no, they don't.  just like netfilter or router-on-linux is smart enough to 
be able to re-code an IP checksum by unmasking and re-masking the old/new 
values in a header, so does the most router vendor's code.

secondly, why would a router or switch even be touching the data at layer-4 
(TCP), let alone recalculating a CRC?

i know you really like your "we do ERL 2 in iSCSI" pitch, but lets stick to 
facts here eh?


cheers,

lincoln.