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| Subject: | Re: TCP/IP CRC question |
|---|---|
| Date: | Wed, 6 Oct 2004 13:15:20 -0700 (PDT) |
So that the other layers can do validation checking. Speeds things up. So everytime you see a packet you do not have to read the whole thing. You can just read the header and if that's bad you know the whole thing is bad. --- Jorge Mendez Bonini <jlmb@cableonda.net> wrote:
I've been reading about the TCP/IP protocol stack (TCP/Ilustrated Vol1 by Richard Stevens) lately and since Ethernet is quite common nowadays almost all link layer examples refer to it (I also checked Douglas Comer Internetworking with TCP/IP vol1). I tried searching RFC but found it very time consuming without good results (maybe I'm not used to it...yet) The Ethernet Frame contains a field known as FCS which contains a CRC. Now, my question is: If the CRC is generated from DATA field among others, What's the point of using checksums on the upper protocolos (IP checksums etc..)? Thanks for your time.
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