I think that’s the problem in a nutshell…until every vendor agrees on the size of a “jumbo” packet/frame (and as such, allows that size to be set with a non-numerical configuration flag). As is, every vendor has a default that results in 1500-byte IP MTU, but changing that requires entering a value…which varies from vendor to vendor.
The IEEE *really* should be the ones driving this particular standardization, but it seems that they’ve explicitly decided not to. This is…annoying to say the least. Have their been any efforts on the IETF side of things to standardize this, at least for IPv4/v6 packets? -C > On Mar 9, 2016, at 10:38 PM, Frank Habicht <ge...@geier.ne.tz> wrote: > > Hi, > > On 3/10/2016 9:23 AM, Tassos Chatzithomaoglou wrote: >> Niels Bakker wrote on 10/3/16 02:44: >>> * nanog@nanog.org (Kurt Kraut via NANOG) [Thu 10 Mar 2016, 00:59 CET]: >>>> I'm pretty confident there is no need for a specific MTU consensus and not >>>> all IXP participants are obligated to raise their interface MTU if the IXP >>>> starts allowing jumbo frames. >>> >>> You're wrong here. The IXP switch platform cannot send ICMP Packet Too Big >>> messages. That's why everybody must agree on one MTU. >>> >>> >> Isn't that the case for IXP's current/default MTU? >> If an IXP currently uses 1500, what effect will it have to its customers if >> it's increased to 9200 but not announced to them? > > none. > everyone has agreed on 1500. it is near impossible to get close to > everyone to agree on 9200 (or similar number) and implement it (at the > same time or in a separate VLAN) (Nick argues, and i see the problem). > The agreement and actions of the (various) operators of L3 devices > connected at the IXP is what matters and seems not trivial. > They are not under one control. > > Frank
