Re: New Version Notification for draft-bonica-6man-frag-deprecate-00.txt

[Tore Anderson <[e-mail]>]

* George Michaelson

> One thing I *strongly* agree with: the sentence at 2.2:
> 
>                   The effective MTU for IPv6 is 1280 bytes.
> 
> This is looking compellingly awful, but true to me.

I believe this is a gross exaggeration. I'm running 1500 bytes MTU on
all the clients and servers in my network, and have yet to hear about
significant trouble (there have been a few, but no more than what I get
with IPv4 as well).

So to see if this was only me, I tried to do a simple" wget -6" of all
the URLs listed in the top 100 sites sorted by Alexa rank at
http://www.worldipv6launch.org/participants/?q=1 and looked at what TCP
MSS values I got back:

TCP MSS   Count
---------------
1212      2
1220      6
1380      6
1410      3
1416      1
1420      1
1436      1
1440      67
1460      1
Total     88


Only 9% were operating on the premise that «the effective MTU for IPv6
is [<=] 1280 bytes», while a clear majority of 77% were operating with
an MTU of [>=] 1500.

(I did not get exactly 100 successful TCP handshakes because some URLs
were down, some did not have an IPv6 address published in DNS, while on
the other hand some were giving me HTTP redirects, which results in
multiple handshakes.)

Tore