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Re: Thoughts on increasing MTUs on the internet

  • From: Daniel Senie
  • Date: Thu Apr 12 18:25:22 2007


At 06:09 PM 4/12/2007, David W. Hankins wrote:


On Thu, Apr 12, 2007 at 05:58:07PM -0400, Daniel Senie wrote:
> >> 2. It's no longer necessary to manage 1500 byte+ MTUs manually
> >
> >But for this, there has been (for a long time now) a DHCPv4 option
> >to give a client its MTU for the interface being configured (#26,
> >RFC2132).
>
> Trying to do this via DHCP is, IMO, doomed to failure. The systems
> most likely to be in need of larger MTUs are likely servers, and
> probably not on DHCP-assigned addresses.

If you're bothering to statically configure a system with a fixed
address (such as with a server), why can you not also statically
configure it with an MTU?

Neither addresses interoperability on a multi-access medium where a new station could be introduced, and can result in the same MTU/MRU mismatch problems that were seen on token ring and FDDI. The problem is you might open a conversation (whatever the protocol), then get into trouble when larger data packets follow smaller initial conversation opening packets.


Or you can work with the same assumptions people use today: all stations on a particular network segment must use the same MTU size, whether that's the standard Ethernet size, or a larger size, and a warning sign hanging from the switch, saying "use MTU size of xxxx or suffer the consequences."