ISP IPv6 Routing without RA and Static Gateway

Someking

Got a new ISP and wanted to configure IPv6 as they are using CGNAT for IPv4.
I'm new to IPv6 and still reading documentation on it but from what I can is the ISP just doing things really weirdly? I just need another set of eyes

WAN is set to use DHCPv6 and they are advertising a /56 Prefix.
Contents of /var/etc/dhcp6c.conf
interface ix1 {
send ia-na 0;
send ia-pd 0;
request refreshtime;
script "/var/etc/dhcp6c_wan_dhcp6withoutra_script.sh";
};
id-assoc na 0 { };
id-assoc pd 0 {
prefix-interface ix0 {
sla-id 0;
sla-len 0;
};
};

LAN devices are picking up the /64 that is created by pfsense and the LAN port on the pfsense box
Attached is the WAN Packet Capture of the DHCP Renew
packetcapture-ix1-20260906225613.pcap

I see the WAN is assigned a /128 Address which can't be used for routing.

I was given a Gateway Address in a /64 Subnet by the ISP and not sure how to use it
Can't set it as a static gateway as I get an error that it's not in the same subnet, which is expected.

ISP did confirm they suppress RA traffic on the WAN side so no automatic setup that way.

Is there some specific routing setup I'm missing here?
Is the pfsense box incorrectly setting up the /128 address and it should be assigning something in the /64 that the ISP gateway should be in?

Pfsense box is on 26.07-RELEASE

Bob.Dig

@Someking Please name your ISP and country.

Someking

@Bob.Dig Local ISP Cityside Fiber in US California.

Bob.Dig

@Someking said in ISP IPv6 Routing without RA and Static Gateway:

ISP did confirm they suppress RA traffic on the WAN side so no automatic setup that way.

Not sure, what this means but for a start, set WAN to DHCP6 and disable gateway monitoring, if it is reported as down.
Then set LAN to track WAN. Finally go back to WAN, set nothing but save and apply and you should have IPv6 working. At least that is the usual setup with dynamic IPv6.

Someking

@Bob.Dig
For IPv6 Routing to get Local Link Addresses it uses ICMPv6 Router Advertisements right? Well they don't respond to those and I guess just drop that traffic so unable to get a route out to the internet.

Tried what you suggested and still nothing if I try to ping out to the internet I don't get traffic. I can ping my local LAN IPv6 address fine.
So I assume I'm missing the default route to the Internet but unsure on how I should even be getting it if ISP doesn't do Router Advertisements.

Bob.Dig

@Someking said in ISP IPv6 Routing without RA and Static Gateway:

Can't set it as a static gateway as I get an error that it's not in the same subnet, which is expected.

There is a checkbox in the advanced gateway-settings to Use non-local gateway.

Someking

@Bob.Dig Thanks for the suggestion didn't even know that was there. Was able to get the Gateway enabled but no traffic is working outbound.
At this point the ISP is doing something funky so I'll raise another ticket with them and keep on investigating.

Gertjan

@Someking said in ISP IPv6 Routing without RA and Static Gateway:

interface ix1 {
send ia-na 0;
send ia-pd 0;
request refreshtime;
script "/var/etc/dhcp6c_wan_dhcp6withoutra_script.sh";
};
id-assoc na 0 { };
id-assoc pd 0 {
prefix-interface ix0 {
sla-id 0;
sla-len 0;
};
};

Mine looks the same, and different.

interface ix3 {
	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_dhcp6withoutra_script.sh"; # we'd like nameservers and RTSOLD to do all the work
};
id-assoc na 0 { };
id-assoc pd 0 {
	prefix-interface igc0 {
		sla-id 0;
		sla-len 0;
	};
};

My WAN is ix3, not ix1
My scripts contains comments, yours doesn't ?
Your LAN is ix1, right ?

Our two dhcp56c settings are identical.

My WAN (ix3) interface :

[26.07-RELEASE][root@pfSensebhf.tld]/root: ifconfig ix3
ix3: flags=1008843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST,LOWER_UP> metric 0 mtu 1500
        description: WAN
        options=4e13cbb<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,JUMBO_MTU,VLAN_HWCSUM,LRO,WOL_UCAST,WOL_MCAST,WOL_MAGIC,VLAN_HWFILTER,RXCSUM_IPV6,TXCSUM_IPV6,HWSTATS,MEXTPG>
        ether 90:ec:77:29:39:2a
        inet 192.168.10.4 netmask 0xffffff00 broadcast 192.168.10.255
        inet6 fe80::92ec:77ff:fe29:392a%ix3 prefixlen 64 scopeid 0x8
        inet6 2a01:dead:beef:7c00:47de:4030:93a5:d7e8 prefixlen 64 autoconf pltime 600 vltime 1800
        media: Ethernet autoselect (1000baseT <full-duplex,rxpause,txpause>)
        status: active
        nd6 options=823<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL,STABLEADDR>

so my GUA IPv6 WAN is :
inet6 2a01:dead:beef:7c00:47de:4030:93a5:d7e8 prefixlen 64 or
inet6 2a01:dead:beef:7c00:47de:4030:93a5:d7e8/64 not /128.

My dhcp6c settings :

If we forget for a moment that the dhcp6c also asks for a prefix, and that part works fine, your LAN is operatinnal, it's first of all a dhcp6 client, so it should ask for a GUI IPv6/64 on its it's interface, your WAN. it shouldn't get a /128 as that (imho) is clearly not ok.

What is going to plan just fine : yet one more ISP with a broken IPv6 setup. That's 'normal'.