<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">On Sep 14, 2016, at 12:34 AM, <a href="mailto:s.s.o.n.i.k+a.u.s.n.o.g@gmail.com" class="">s.s.o.n.i.k+a.u.s.n.o.g@gmail.com</a> wrote:<br class=""><div><blockquote type="cite" class=""><span style="font-family: Calibri, sans-serif; font-size: 11pt;" class="">Client firewall MTU set to 1484: Successful reply at length 1456. Unsuccessful at 1457, however echo request is seen, and unreachable 3:4 message is returned by firewall, but never arrives at the source.</span><br class=""></blockquote><div><br class=""></div>Ethernet firewall? Why is the MTU so low?</div><div><br class=""></div><div>These problems are virtually always caused by a firewall blocking ICMP. Usually it’s a firewall operated by the person who is complaining about PMTUD not working :-)</div><div><br class=""></div><div> - mark</div><div><br class=""></div><div><br class=""></div></body></html>