ping6 and a do-not-fragment option

[Richard A Steenbergen]

Hi,

I just noticed, while trying to do a little debugging, that ping6
doesn't seem to have a way to specify "do not fragment" like ping does
for IPv4. Obviously the way this is implemented has been changed, since
there is no longer a DF-bit in IPv6, but it looks like there is already
an IPV6_DONTFRAG setsockopt() available for exactly this purpose. It 
looks like IPV6_DONTFRAG got added at a later date (from RFC3542), 
perhaps after ping6 was initially written.

It seems like the correct fix would be to add a cli option to ping6
(perhaps 'D', since it's available and matches the command in ping) to
call this setsockopt() and implement a "do not fragment" option.

-- 
Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)