On Tue, Feb 2, 2010 at 10:15 PM, Xu Xiaohu <x...@huawei.com> wrote: > > >> -----邮件原件----- >> 发件人: rrg-boun...@irtf.org [mailto:rrg-boun...@irtf.org] 代表 Christopher >> Morrow >> 发送时间: 2010年2月3日 11:00 >> 收件人: Tony Li >> 抄送: RRG; Robin Whittle >> 主题: Re: [rrg] SEAL critique, PMTUD, RFC4821 = vapourware >> >> On Thu, Jan 28, 2010 at 2:25 AM, Tony Li <tony...@tony.li> wrote: >> > Robin Whittle wrote: >> > >> >> I argue against Fred Templin's position that >> >> ordinary RFC1191 DF=1 Path MTU Discovery (and >> >> therefore its RFC1981 IPv6 equivalent) is "busted". >> >> >> >> Where is the evidence that networks filtering out >> >> PTB (Packet Too Big) messages is a significant >> >> problem? >> > >> > >> > This happens. Consult some operator folks, privately and quietly. Many >> > enterprises blocked all inbound ICMP when DDoS attacks started happening. >> >> yes, not just for 'dos attack' problems but because often people don't >> understand what ICMP is there for :( the dreaded 'people can ping >> you!!' apparently == 'deny icmp any any' > > Yes, based on the above practice, some router vendors even give up the > support for PMTUD in their router OSes.
that seems like a VERY BAD PLAN, being dumb and turning a knob off is one thing, removing the knob is entirely different (and far worse). > > Xiaohu > >> PMTUD is horrendously supported :( >> >> -chris >> (operatorish guy) >> _______________________________________________ >> rrg mailing list >> rrg@irtf.org >> http://www.irtf.org/mailman/listinfo/rrg > > _______________________________________________ rrg mailing list rrg@irtf.org http://www.irtf.org/mailman/listinfo/rrg
