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Re: exchange point media (was: Re: MAE-EAST Moving? ...)
This is a problem for many switches that support non-ethernet interfaces. RFC1191 does not apply to switches (only routers), but it probably should. I've run into this problem with switches from Fore and Cabletron. I would bet that this is a problem for most switches. JMH Jeff Haas wrote: ... > Should one install a (fast|gig)ethernet card into one's Gigaswitch > and said switch have FDDI interfaces, the switch will go from having > a 4500+ byte MTU to a 1500 byte MTU. This is even between FDDI card > to FDDI card on the same switch. > > The switch will happily fragment the packet if you leave DF off. > However, if you turn it on, the switch will drop the packet silently. > The switch is unable to generate ICMP and route it back to the > sender. > > Given all of this, PMTU-D breaks in these circumstances. ... > -- > Jeffrey Haas - Merit RSng project - firstname.lastname@example.org -- John Hall <email@example.com> F5 Networks, Inc. Senior Test Engineer 206-505-0800 It is up to us to produce better-quality movies. -- Lloyd Kaufman, producer of "Stuff Stephanie in the Incinerator"