Re: Is Fragmentation at IP layer even needed ?

[Fernando Gont <[e-mail]>]

Hi, David,

On 02/08/2016 03:56 PM, David Borman wrote:
> 
>> On Feb 8, 2016, at 12:23 PM, Warren Kumari <[e-mail]>
>> wrote:
> ...
>> On Mon, Feb 8, 2016 at 9:05 AM David Borman <[e-mail]>
>> wrote:
> ...
>> So if you are writing an application that needs >1500 octets, use
>> an IPv6 implementation that supports >1500 octet fragmentation and
>> reassembly.
>> 
>> ... but as an application writer (or, basically anyone else), I
>> have no control over the "IPv6 implementation". Even if I'm in an
>> environment where I do control the OS / model of all devices, and I
>> know they support >1500 octet, it seems like a bad idea to *rely*
>> on that. Sometime I'm going to want to change OS / add some other
>> device, be able to interact with some other system. This sounds
>> like vendor lock at its worst…
> 
> If you wind up in a scenario where you get locked to a particular OS
> vendor because it’s the only one that supports IPv6 fragmentation
> >1500 octets, then that is probably the least of your worries.  I’d
> be much more worried about IPv6 fragmentation in light of Ron
> Bonica’s comment that intermediary nodes drop packets with extension
> headers, which is bad news even for fragmented packets in the
> 1280-1500 range.

FWIW, when communicating with public {web, mail, DNS} servers, you get
packet drop rates of over 25% if you employ IPv6 fragmentation.

(My pleasure to hear from you ;-) )

Thanks,
-- 
Fernando Gont
SI6 Networks
e-mail: [e-mail]
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