intermittent IPv6 connectivity between LAN to WAN (through firewall) but not from firewall itself to upstream gateway

  • Well, here goes. Thanks for reading.

    Our library is fortunate enough to have a gigabit Internet connection provided by MSLN (University of Maine System). IPv4 is not a problem. We are running a new SG-5100
    and the WAN is jacked directly into the MSLN-provided Edge Router. There is a little IPv6 network /126 between the two, such that the ER is 2610:48:433b:1::1 and the pfSense WAN is ::2 and from the pfSense shell I can always without fail ping ::1 and always ping the IPv6 Internet ( for example). The internal networks are
    each assigned their own /64 such that the LAN iface is 2610:48:433b:2:: and DHCPv6 is configured to hand out a range plus DNS, and RA for the router, to LAN clients, example:

    eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP group default qlen 1000
    link/ether b8:27:eb:14:24:57 brd ff:ff:ff:ff:ff:ff
    inet brd scope global eth0
    valid_lft forever preferred_lft forever
    inet6 2610:48:433b:2::29c/128 scope global noprefixroute dynamic
    valid_lft 5164sec preferred_lft 2464sec
    inet6 2610:48:433b:2:84c3:ee4b:d718:f529/64 scope global mngtmpaddr noprefixroute dynamic
    valid_lft 86391sec preferred_lft 14391sec
    inet6 fe80::9659:f211:a65c:2648/64 scope link
    valid_lft forever preferred_lft forever

    For brevity, LAN hosts can't always ping6 the Edge Router upstream of the WAN nor can they ping the firewall's WAN interface (!) , and therefore can't always reach the IPv6 Internet. This comes and goes without seeming to have a reason, hence I write this treatise for help. However, the firewall itself, via it's shell, can ALWAYS ping the ER upstream and can ALWAYS ping the IPv6 Internet.
    So something is rotten between the LAN hosts and the firewall's WAN interface. Firewall rules are simple LAN IPv4/6 allow to any, it should be a straight shot (no NAT).

    Oh and if the problem lies with this new fangled Unifi Switch I just installed recently I'm going to throw it in the ocean and reinstall the old ProCurve that was working perfectly albeit incredibly loudly (bad fan, hence the upgrade). It's the only thing that lies between the LAN hosts and the SG-5100.

    I don't think the problem lies with MSLN although I did open a ticket with their support just in case it's the Edge Router gone wonky.

    Any ideas?

  • @fossicker Also I can always ping the Edge Router's IPV6 address from the wild and wooly Internet (my home connection via HE tunnel broker). For diagnostics I have the WAN open to ICMPv6 and I can always ping that too from outside. It's not a DNS problem,
    that much I know.

  • LAYER 8 maybe this apply to you also :)

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