On Mon, Jun 04, 2007 at 12:03:57PM +0800, Wei Yongjun wrote: > > So I want to know how the route announce a MTU larger then 576, such as > 1280? RFC says ICMP error message return as much as we can without > exceeding 576 bytes.
I think there is a misunderstanding here. The RFC is talking about how much of the payload may be included in the ICMP packet. It is not talking about the length field in the original IP header. That must be left untouched. > And ipv4 router alaways return as a packet size 576 because of this. > If MTU is greater then 576, HOST will used "mtu = guess_mtu(old_mtu)" to > get a MTU. Method of send ICMP Fragmentation Needed message is > difference from receive, Which router is doing that? Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} <[EMAIL PROTECTED]> Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt - To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
