Casper.Dik at Sun.COM wrote:
>> Interface Classification Comments
>> -------------------------------------------------------------
>>
>> ping -D option Committed ping(1M)
>> ping -F option Committed traceroute(1M)
>> -------------------------------------------------------------
>
> "traceroute -F option", surely?
Oops, yes.
>> -F
>> Turn off path MTU discovery. For IPv4 this means setting
>> the Don't Fragment bit. For IPv4 and IPv6 this means to
>> not allow fragmentation as the datagrams are sent. If
>> the packetlen exceeds the MTU, then traceroute may
>> report that sending failed due to Message too long.
>> ---
>
>
> This sounds wrong. If you set the "don't fragment bit" then you ARE doing
> path MTU discovery. I think we only do this on TCP/IP and we don't
> do this for ICMP (ping) or UDP (traceroute).
FWIW we've been doing it for all traffic including ICMP/RAWIP and UDP
since Solaris 2.0.
I've struggled with the description and trying to find a way to describe
it that is common for IPv4 and IPv6. And you are right that saying "Turn
off path MTU discovery" is odd at best. Thus I think it should say "Turn
of fragmentation" as the first sentence for -D and -F.
Does that make more sense?
Erik
>
> Casper
>
