Thoughts on increasing MTUs on the internet

Thu Apr 12 09:20:18 UTC 2007

Dear NANOGers,

It irks me that today, the effective MTU of the internet is 1500  
bytes, while more and more equipment can handle bigger packets.

What do you guys think about a mechanism that allows hosts and  
routers on a subnet to automatically discover the MTU they can use  
towards other systems on the same subnet, so that:

1. It's no longer necessary to limit the subnet MTU to that of the  
least capable system

2. It's no longer necessary to manage 1500 byte+ MTUs manually

Any additional issues that such a mechanism would have to address?