I'm submitting this fast-track for Erik Nordmark, it times out on
10/02/2009. The release binding is Patch.
Background:
----------
Since Solaris 2.0 we have enabled path MTU discovery by default
including for UDP and RAWIP sockets. The addition of IP_DONTFRAG
[PSARC/2009/494] allows applications to control this.
Solaris implements traceroute -F ("dontfrag") to disable path MTU
discovery for traceroute. But this is documented as not working in
zones. And the implementation doesn't do it for IPv6 at all.
BSD implements a -D option to ping(1m) to enable path MTU discovery just
like "-F" does it for traceroute. Solaris does not currently implement
this option.
Details:
-------
This case is to introduce ping -D in Solaris and remove the limitations
for traceroute -F..
The behavior of ping and traceroute when these options (-D and -F
respectively) are not specified is unchanged.
Exported Interfaces
-------------------------------------------------------------
Interface Classification Comments
-------------------------------------------------------------
ping -D option Committed ping(1M)
ping -F option Committed traceroute(1M)
-------------------------------------------------------------
Man page updates:
================
Add this text to ping(1M):
-D
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 data_size exceeds the MTU, then ping may report
that sending failed due to Message too long.
Change the text in traceroute(1M) from:
-F
Set the "don't fragment" bit. This option is valid only
on IPv4. When specified from within a shared-IP zone,
this option has no effect as the "don't fragment" bit is
always set in this case.
to:
-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.
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