Is there a way to turn off TCP checksumming in linux or windows? It's easy to turn off in lwIP, but the linux/windows client then drops the packets with bad checksums.
Rishi > [EMAIL PROTECTED] wrote: >> Kieran Mansley wrote: >>> On Mon, 2008-10-13 at 08:58 -0400, bill wrote: >>>> TCP checksum (which we in the end disabled because we are always on an >>>> internal lan) >>> I hope you're not transferring any important data over this connection. >>> I would not trust any network to get the bits right all the time. It >>> would be fine for a large class of applications (e.g. where the data >>> has >>> no persistence when it arrives, or for those that would often use UDP) >>> but a really bad idea for others. >>> >> I agree on this. We only discovered a bug in one MAC because of TCP >> checksum errors. The MAC said the CRC was correct... >> >> Simon > Why? The Ethernet 32bit CRC is lightyears better than the 16 bit TCP > checksum at detecting errors (unless your MAC is broken of course...) > Modern industrial Ethernet protocols for example cannot afford a lot of > overhead per packet, so they rely entirely on the Ethernet CRC. > > Which reminds me... I read somewhere that the effectiveness of the > Ethernet CRC drops somewhat at a magic packet size somewhere around 9k. > So if data integrity is important, you should not use 16k jumbo frames. > > 4k jumbo frames may be useful in some systems if it means you can use > the MMU to move the payload around rather than having to copy it. > > /Timmy Brolin > > > _______________________________________________ > lwip-users mailing list > [email protected] > http://lists.nongnu.org/mailman/listinfo/lwip-users > > _______________________________________________ lwip-users mailing list [email protected] http://lists.nongnu.org/mailman/listinfo/lwip-users
