Thanks to all of you that responded. I now have every working with the information you provided. This is what I ended up with File: /etc/systemd/networkd.conf.d/10-forwarding.conf [Network] IPv4Forwarding=true IPv6Forwarding=true Two .link files to rename the interfaces to "internal" and "external" based on MAC Address of NIC. File: /etc/systemd/network/internal-if.network [Match] Name=internal [Network] Description=internal network Address=172.17.1.1/24 IPForward=ipv6 DNS=127.0.0.1 IPv6SendRA=true DHCPPrefixDelegation=true The IPv6SendRA=true and DHCPPrefixDelegation=true settings make the clients on the internal network get sent what they need to come up correctly. File: /etc/systemd/network/ppp0-if.network [Match] Name=ppp0 [Network] Description=external network Address=2001:xxx:xxx:1 IPv6AcceptRA=true UseDelegatedPrefix=true I set explicit IPv6AcceptRA=true and UseDelegatedPrefix=true here at the external side. I have a pppoe.service that brings up the ppp0 interface Barry |