Re: [tsvwg] draft-ietf-udp-options issues from IETF 104

[Joe Touch <[e-mail]>]

On 2019-07-16 14:37, Tom Herbert wrote:

> On Tue, Jul 16, 2019 at 2:25 PM Joe Touch <[e-mail]> wrote: 
> 
>> ...
> IPv6 extension headers began without a limit, and then we realized we
> needed to limit them to fit into one MTU, and then we realized that
> unbounded limits are a good DOS attack vector so we added more limits
> to the receiver which are now default in Linux. Saying that we need
> unlimited options is an academic statement and doesn't reflect
> realities of deployment.

We CAN easily set a limit IF we went. 

We don't need to design that into the protocol structure. And we don't
need to start with something that already impacts things like
fragmentation/reassembly, LITE, etc. where the final user data is inside
the options area. 

Additionally, the comparison to IP is misleading; these are endpoint
options and should not have the same kinds of limits as per-hop. 

Finally, the "realities of deployment" should not be designed or limited
by what is currently available. UDP hasn't been updated in many decades;
I hope we won't need to come back and re-do this in 5 years just because
we're too focused on current technology. 

Joe