Comcast IPv6 broken after reboot. WAN release / renew resolves

[badbroccoli]

I have been dealing with an annoyance for several months now. Every time my OPNsense box reboots, IPv6 routing to the internet is broken until I release/renew the WAN interface. Internal routing seems to work just fine. I have a /60 from Comcast. Can be working fine for weeks, do a reboot, IPv4 comes back fine, WAN interface has an IPv6 address, but clients can't route out. Was wondering if anyone has seen similar and knows what the hell is going on, or can point me in the right direction. I've seen others report this but not sure I've seen a solve. Thanks in advance :)

Details:

OPNsense 22.7.10_2-amd64
WAN interface configured for DHCPv6 in Basic mode, with prefix delegation hint sent at /60
Internal clients configured for Track Interface tracking the WAN interface
Router advertisements configured for Managed, router priority High. RA mode "Assisted" also has issue. Advertise default gateway is checked.

Similar thread from pfsense 6 years ago - https://www.reddit.com/r/PFSENSE/comments/6gk5np/issue_with_comcast_ipv6_requires_dhcp/

Code Select Expand


me@opnsense:/var/etc % cat dhcp6c.conf
interface ixl3 {
  send ia-na 0; # request stateful address
  send ia-pd 0; # request prefix delegation
  request domain-name-servers;
  request domain-name;
  script "/var/etc/dhcp6c_wan_script.sh"; # we'd like some nameservers please
};
id-assoc na 0 { };
id-assoc pd 0 {
  prefix ::/60 infinity;
  prefix-interface vlan0.1.2 {
    sla-id 2;
    sla-len 4;
  };
  prefix-interface igb0 {
    sla-id 0;
    sla-len 4;
  };
};

me@opnsense:/var/etc % cat dhcp6c_wan.conf
interface ixl3 {
  send ia-na 0; # request stateful address
  send ia-pd 0; # request prefix delegation
  request domain-name-servers;
  request domain-name;
  script "/var/etc/dhcp6c_wan_script.sh"; # we'd like some nameservers please
};
id-assoc na 0 { };
id-assoc pd 0 {
  prefix ::/60 infinity;
  prefix-interface vlan0.1.2 {
    sla-id 2;
    sla-len 4;
  };
  prefix-interface igb0 {
    sla-id 0;
    sla-len 4;
  };
};

me@opnsense:/var/etc % cat radvd.conf
# Automatically generated, do not edit
# Generated for DHCPv6 server opt4
interface vlan0.1.2 {
AdvSendAdvert on;
MinRtrAdvInterval 120;
MaxRtrAdvInterval 600;
AdvLinkMTU 1500;
AdvDefaultPreference high;
AdvManagedFlag on;
AdvOtherConfigFlag on;
prefix my:ipv6:prefix:382::/64 {
DeprecatePrefix on;
AdvOnLink on;
AdvAutonomous on;
};
RDNSS fd4e:9ee1:fc79:4db6:a4ab:44ff:feac:c11d {
};
DNSSL lan {
};
};
# Generated config for dhcp6 delegation from wan on lan
interface igb0 {
AdvSendAdvert on;
AdvLinkMTU 1500;
AdvManagedFlag on;
AdvOtherConfigFlag on;
prefix my:ipv6:addr:prefix::/64 {
DeprecatePrefix on;
AdvOnLink on;
AdvAutonomous on;
};
RDNSS my:external:ipv6:address:of:the:wan:interface { };
DNSSL lan { };
};