[HECnet] What use are *you* making of HECnet?

Paul Koning Paul_Koning at dell.com
Thu Feb 26 10:53:47 PST 2009


"Jason" == Jason Stevens <neozeed at gmail.com> writes:

As for fragmentation... Now I assume you are talking about the
encapsulation of ethernet packets in UDP packets. Those will be a
bit larger still, and will almost certainly be fragmented when
sent over the internet, yes. I don't see a problem with that. Do
you?


Jason> Well if you were trying to send the whole 1500 bytes of data +
Jason> headers in the UDP packet won't it cut stuff off? 

No, not unless it's either IPv6, or you set the "don't fragment" flag
in the IP header.   IPv4 will fragment oversized packets no matter
what's inside, and indeed this is the only way for random size
UDPgrams to get where they are going.   It should work fine.   Note that
fragmentation is often not all that efficient.   Compared with the
performance of old 10Mb/s DEC Ethernet gear, that's unlikely to be an
issue.

          paul



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