Re: packet loss question

[cpolish () surewest net]

On 2016-07-11 11:26, Mark Andrews wrote:
> In message <25577FE1-6366-4D6D-B82E-A779193CB458 () beckman org>, Mel Beckman writ
> The Internet Standard MTU's are 68 octets for IPv4 (RFC 791) and
> 1280 octets for IPv6 (RFC 2460).
>
> Every size greater than those is subject to negotiation.  Now most
> paths pass packets greater than those values.  Ethernet is very
> common and passes 1500.

Thanks for identifying the source, I wish more people did this. 
My nitpick is that RFC791 doesn't label MTU=68 as "standard"; 
it says (section 3.2, p.25):

    Every internet module must be able to forward a datagram of 68
    octets without further fragmentation.  

More to your point, RFC791 also says (section 3.1, p. 13):

    All hosts must be prepared to accept datagrams of up to 576
    octets (whether they arrive whole or in fragments).  It is
    recommended that hosts only send datagrams larger than 576
    octets if they have assurance that the destination is prepared
    to accept the larger datagrams.
 
> Encapsulated / translate traffic is also very common and has MTUs
> < 1500 and affects BOTH IPv4 and IPv6 data streams and will become
> more so as we move from dual stack to IPv6 only where IPv4 is a
> service running on top of IPv6.

-- 
Charles Polisher