-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On 24/03/14 09:02, Dirkjan Ochtman wrote: > On Mon, Mar 24, 2014 at 6:08 AM, Martin Sustrik > <sustrik@xxxxxxxxxx> wrote: >> That obviously entails that all messages exceeding path MTU will >> be dropped silently. > > Would it be possible to do that non-silently? Not really. Without PMTU discovery you don't know what the minimal MTU is on the path. So you send a packet and expect it will get through. When a router gets a packet it cannot forward it it will drop it and send an ICMP notification back to the sender. However, ICMP itself is unreliable, so the sender may not be notified at all. Martin -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTL+hzAAoJENTpVjxCNN9Y8wcIAJJIVxk05f7I6KrXJT0xMm2Q i4qiNvmkW5HVIOM8m9kfs7KDAzRfVBkCpmyBj58vup05Wl6sIQ+p31GRUo+iL0pO TweVe3t7ro/M2Xev5xlDQjVPmbgFiEA6YvMiWHsuh3qCnJcdT/GHLFNL/0i1Ctr5 MTiq2cmSJSvukxCAMcDS+cc8wHhO2buMU7i3zKG16Ef3jsDzSqwBebWMfCsNf0J8 qr+H5vEed1bd3GQLbvMMuJsbPo8B3a5i75rlvDvAymQUkhXBGXZzYQZZZYgLzEp8 ys2r8ujCIEL5S5KASmlPsSMIvgW9FJUJIjpgov7S/woTaI5vHt6CmRCGhtIDWI0= =/gyl -----END PGP SIGNATURE-----