Posted Jul 10, 2004 2:53 UTC (Sat) by Ross
In reply to: TCP window scaling and broken routers
Parent article: TCP window scaling and broken routers
You misunderstand the standard: "must be zero" means that they must be
set to zero for software adhering to this version of the standard. They
absolutely must be ignored by software adhering to that version of the
standard. If they are dropped when not zero then the implementation is
broken because it is not upwards-compatible with other implementations.
TCP/IP is specifically designed to be upwards compatible. If you don't
understand options you are supposed to ignore them, otherwise there is
no point in having an extendable protocol.
But in any case, even for those who can't read RFCs properly, there was a
draft RFC at the time and it's now official. So there are absolutely,
positively no excuses anymore but there are still lots of broken vendors
and even more unpatched routers and firewalls (one only wonders what
security problems these systems must have).
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