From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mika Liljeberg Subject: Re: SCTP path mtu support needs some ip layer support. Date: 14 Jan 2003 22:11:06 +0200 Sender: netdev-bounce@oss.sgi.com Message-ID: <1042575066.2610.26.camel@devil> References: Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Cc: kuznet@ms2.inr.ac.ru, jgrimm2@us.ibm.com, davem@redhat.com, netdev@oss.sgi.com Return-path: To: Sridhar Samudrala In-Reply-To: Errors-to: netdev-bounce@oss.sgi.com List-Id: netdev.vger.kernel.org On Tue, 2003-01-14 at 20:44, Sridhar Samudrala wrote: > Frankly, i haven't thought of IPV6 in detail. I was under the impression that > it is simpler in ipv6 as only source is allowed to do fragmentation and as there > is no DF bit, it will automatically fragment any packets larger than the pmtu. > But looking at ip6_xmit(), i realize that ICMPV6_PKT_TOOBIG error is generated > forcing the transport layer to do the fragmentation. TCP can handle this, but > SCTP cannot. IPv6 is simpler, because the specification asserts that every IPv6 capable link must support a MTU of at least 1280 bytes. If you don't generate packets larger than this you don't have to worry about fragmentation. If you want larger data chunks, then you have to solve this for IPv6 as well. MikaL