…icated an MTU < 1280. It is believed that firewalls violating Section 4.3.1 of [RFC4890] are at fault. Both failures (the 5% wrong response when MTU = 1280 and the 57% wrong response when MTU < 1280) will cause PMTUD black holes [ RFC2923 ]. Unfortunately, the translator cannot i…

… to "black-holed" connections caused by the filtering of ICMPv6 messages. See [ RFC4890 ] for recommendations regarding filtering ICMPv6 messages. 7 . IANA Considerations This document does not require any IANA actions. 8 . References 8.1 . Normative References [ ICMPv6 ] Conta, …

…iscovery are being increasingly filtered by middleboxes (including Firewalls) [ RFC4890 ]. When the path includes a tunnel, some devices acting as a tunnel ingress discard ICMP messages that originate from network devices over which the tunnel passes, preventing these from reachi…

…RFC4443]). * ICMP messages can be filtered by middleboxes, including firewalls [RFC4890]. A firewall could be configured with a policy to block incoming ICMP messages, which would prevent reception of PTB messages by a sending endpoint behind this firewall. * When the router issu…

… to "black-holed" connections caused by the filtering of ICMPv6 messages. See [ RFC4890 ] for recommendations regarding filtering ICMPv6 messages. 7 . IANA Considerations This document does not require any IANA actions. 8 . References 8.1 . Normative References [ ICMPv6 ] Conta, …