comcast ipv6 + pfsense

These are some notes that helped get IPv6 working on pfSense with Comcast Business as the ISP using IPs dynamic IPs. Some of the configuration below is arbitrary and unique to my preferences for the particular setup involved. This setup assumes that IPv4 works, pfSense in general works, and IPv6 firewall rules are in place to allow traffic as appropriate.

This particular setup involves multiple VLANs and a single WAN.

  1. Navigate to: Interfaces > "your WAN interface"
  2. Change IPv6 Configuration Type to DHCP6
  3. Under “DHCP6 Client Configuration”:
    1. Change DHCPv6 Prefix Delegation size to 60
    2. ☑️ Send IPV6 prefix hint
    3. ☑️ Do not wait for RA
    4. ☑️ Do not allow PD/Address release
    5. Save and Apply Settings
  4. For each LAN/VLAN, navigate to their respective interfaces under the Interfaces menu and do the following:
    1. Change DHCPv6 Configuration Type to Track Interface
    2. Under Track IPv6 Interface, change IPv6 Interface to your WAN interface
    3. Change IPv6 Prefix ID to 0, and increment per interface.
    4. Save and Apply Settings
  5. For each LAN/VLAN, navigate to their respective interfaces under the Services menu > DCHPv6 Server & RA
    1. Select the Router Advertisements tab
    2. Change Router mode to Stateless DHCP
    3. Change Router priority to High
    4. Save and Apply Settings

At this point, you should see IPv6 address show up for each interface configured on the Status > Dashboard. You may need to reboot the router and/or modem as well. Additionally, connected devices should receive IPv6 addresses.