Nov 30, 2018 · Any other hop limit makes those ICMPv6 messages invalid and will be discarded Those ICMPv6 messages are NEEDED for IPv6 to work. PfSense running on Qotom mini PC i5 CPU, 4 GB memory, 32 GB SSD & 4 Intel Gb Ethernet ports.

Jan 18, 2021 · ICMPv6 over the Internet is important for Path MTU Discovery (which uses the ICMPv6 Packet Too Big message) since ipv6 routers don't fragment packets. But I don't know if the web page tests that. I think they may be testing ICMPv6 echo request.

Sep 11, 2018 · That test just needs ICMPv6 Echo Requests to be passed. Any other critical ICMPv6 packets (which I personally don’t consider Ping to be among) are already allowed behind-the-scenes by pfSense. Allowing all ICMPv6 could actually pose a security threat because of some of its uses within a network as far as neighbor discovery and whatnot.

May 26, 2022 · Certain ICMPv6 traffic should be allowed for proper IPv6 functionality. It is more important than with IPv4. I linked to the RFC 4890 document for the technical reasoning behind it. It is possible that blocking ICMPv6 completely will cause connectivity issues.

Apr 15, 2018 · Still looking for where the ICMPv6 is being dropped. Firewall logs do show dumped ICMPv6 packets dumped, though the log doesn't tell too much (type etc). Guess I will have to get tcpdumps and look at them… Any more ideas would be helpful (e.g. were are the hidden rules visible) but I certainly thank you all for your help.

Jan 21, 2019 · HELP (Firewall) - Allow ICMPv6 for IPv6 Finally got IPv6 to work on Spectrum internet after hours of fighting. On the IPv6 test I get 18/20 with the only warning being that ICMP is being filtered.

Jun 22, 2012 · IPv6 firewalls need to permit ICMPv6, type 2 (Packet Too Big) to work correctly with the public Internet. If you are implementing the IPv6 firewall for your web site, your enterprise, or other organization, please permit this specific ICMPv6 message, even if you by default block other types of ICMP.

Jul 9, 2020 · Allowing ICMPv6 I was troubleshooting an IPv6 problem with a particular machine on my network today and ended up at ipv6-test.com . I got a 17/20 score at that site with a message indicating " Your router or firewall is filtering ICMPv6 messages sent to your computer.

Apr 27, 2020 · RFC 4890 recommends which ICMPv6 types should be allowed by firewalls. tl;dr look at sections 4.3.1 and later Edit: 4.3.1 covers this, but I just wanted to note that Packet Too Big is probably the most overlooked ICMPv6 type and has caused trouble for many v6 newbies, especially those using tunneled connections.

Apr 29, 2017 · It can be a problem. IPv6 relies on something calling PMTUD (Path MTU Discovery) to work. Blocking ICMPv6 prevents PMTUD from working. Unfortunately, unblocking ICMPv6 has a downside. It can expose your devices to a certain kind of DoS attack (atomic fragment attack). This puts you in a "Damned if you do. Damned if you don't." situation.