dennis@jnx.COM (Dennis Ferguson) writes:
>Here's the top 10 IP packet sizes as measured from a backbone router

>Size (bytes)  Probability (%)
>    40           44.8
>   552            9.2


>I'd conclude two things:

>(2) 296 is so frequently occurring that I wouldn't want to bet the problem
>    is entirely the fault of the Microsoft software, as one would assume
>    they would have had plenty of opportunity to notice by now and fix it
>    (I'm pretty sure the 552 in second place is microsoft's preferred number,
>    so there may be a lot of those machines out there).

The 552 being in second place has most likely nothing to do with
microsoft.  Some BSDish TCP/IP stack default to a 512 byte maximum
segment size for non-local traffic.  To qoute from /sys/netinet/tcp.h:

/*
 * Default maximum segment size for TCP.
 * With an IP MSS of 576, this is 536,
 * but 512 is probably more convenient.
 * This should be defined as MIN(512, IP_MSS - sizeof (struct tcpiphdr)).
 */
#define TCP_MSS 512

Interestingly enough, this used to be 536 bytes in 4.3BSD.
-- 
Christoph Badura	bad@flatlin.ka.sub.org

You don't need to quote my .signature.  Everyone has seen it by now.
Besides, it doesn't add anything to the current thread.