Can't obtain IPv6 address from ISP

Installing and Using OpenWrt Network and Wireless Configuration
1

I recently switch to OpenWRT and most of my network is setup and runs well. I have only one problem with IPv6 addresses. Generally, my OpenWRT router (RT 3200, OpenWRT 22.03) is connected to a Draytek Vigor 167 VDSL modem via the WAN port. I establish a PPoE connection to my ISP (Deutsche Telekom VDSL2) via the WAN interface. I also get an IPv4 address assigned and everything works fine. I set the WAN6 interface to DHCPv6 client, the device as alias to wan (@wan). However, WAN6 does not get any IPv6 addresses assigned, the interface overview only says "Protocol: Alias Interface (DHCPv6 client)", without any further details.

Here's the content of me /etc/config/networks

config interface 'loopback'
        option device 'lo'
        option proto 'static'
        option ipaddr '127.0.0.1'
        option netmask '255.0.0.0'

config globals 'globals'
        option ula_prefix 'xxx::/48'

config device
        option name 'br-lan'
        option type 'bridge'
        list ports 'lan1'
        list ports 'lan2'
        list ports 'lan3'
        list ports 'lan4'

config interface 'lan'
        option proto 'static'
        option ipaddr '192.168.1.1'
        option netmask '255.255.255.0'
        option device 'br-lan.1'
        option delegate '0'
        option ip6assign '64'
        option ip6hint '1'
        option ip6ifaceid '::1'

config interface 'wan'
        option device 'wan'
        option proto 'pppoe'
        option username 'xxx'
        option password 'xxx'
        option ipv6 'auto'

config interface 'wan6'
        option proto 'dhcpv6'
        option reqaddress 'try'
        option reqprefix 'auto'
        option device '@wan'

config bridge-vlan
        option device 'br-lan'
        option vlan '1'
        list ports 'lan1:t*'
        list ports 'lan4:u*'

config bridge-vlan
        option device 'br-lan'
        option vlan '2'
        list ports 'lan1:t'

config bridge-vlan
        option device 'br-lan'
        option vlan '3'
        list ports 'lan1:t'

config bridge-vlan
        option device 'br-lan'
        option vlan '4'
        list ports 'lan1:t'

config bridge-vlan
        option device 'br-lan'
        option vlan '5'
        list ports 'lan1:t'
        list ports 'lan2:u*'
        list ports 'lan3:u*'

config interface 'dmz'
        option proto 'static'
        option device 'br-lan.2'
        option ipaddr '192.168.20.1'
        option netmask '255.255.255.0'
        option delegate '0'
        option ip6assign '64'
        option ip6ifaceid '::1'

config interface 'guest'
        option proto 'static'
        option device 'br-lan.3'
        option ipaddr '192.168.30.1'
        option netmask '255.255.255.0'
        option delegate '0'
        option ip6assign '64'
        option ip6ifaceid '::1'

config interface 'phone'
        option proto 'static'
        option device 'br-lan.4'
        option ipaddr '192.168.40.1'
        option netmask '255.255.255.0'
        option delegate '0'

config interface 'iot'
        option proto 'static'
        option device 'br-lan.5'
        option ipaddr '192.168.50.1'
        option netmask '255.255.255.0'

config device
        option name 'wan'

config device
        option name 'pppoe-wan'
        option type 'tunnel'

and /etc/config/dhcp

config dnsmasq
        option domainneeded '1'
        option localise_queries '1'
        option rebind_protection '1'
        option rebind_localhost '1'
        option local '/lan/'
        option domain 'lan'
        option expandhosts '1'
        option authoritative '1'
        option readethers '1'
        option leasefile '/tmp/dhcp.leases'
        option resolvfile '/tmp/resolv.conf.d/resolv.conf.auto'
        option localservice '1'
        option ednspacket_max '1232'

config dhcp 'lan'
        option interface 'lan'
        option start '100'
        option limit '150'
        option leasetime '12h'
        option dhcpv4 'server'
        option dhcpv6 'server'
        option ra 'server'
        list ra_flags 'managed-config'
        list ra_flags 'other-config'

config dhcp 'wan'
        option interface 'wan'
        option ignore '1'

config dhcp 'wan6'
        option interface 'wan6'
        option ignore '1'
        
config odhcpd 'odhcpd'
        option maindhcp '0'
        option leasefile '/tmp/hosts/odhcpd'
        option leasetrigger '/usr/sbin/odhcpd-update'
        option loglevel '4'

config dhcp 'dmz'
        option interface 'dmz'
        option start '100'
        option limit '150'
        option leasetime '12h'
        option ra 'server'
        option dhcpv6 'server'

config dhcp 'guest'
        option interface 'guest'
        option start '100'
        option limit '150'
        option leasetime '12h'
        option ra 'server'
        option dhcpv6 'server'

config dhcp 'phone'
        option interface 'phone'
        option start '100'
        option limit '150'
        option leasetime '12h'

config dhcp 'iot'
        option interface 'iot'
        option start '100'
        option limit '150'
        option leasetime '12h'

and /etc/config/firewall

config defaults
        option input 'ACCEPT'
        option output 'ACCEPT'
        option forward 'REJECT'
        option synflood_protect '1'

config zone
        option name 'lan'
        option input 'ACCEPT'
        option output 'ACCEPT'
        option forward 'ACCEPT'
        list network 'lan'

config zone
        option name 'wan'
        option input 'REJECT'
        option output 'ACCEPT'
        option forward 'REJECT'
        option masq '1'
        option mtu_fix '1'
        list network 'wan'
        list network 'wan6'

config forwarding
        option src 'lan'
        option dest 'wan'

config rule
        option name 'Allow-DHCP-Renew'
        option src 'wan'
        option proto 'udp'
        option dest_port '68'
        option target 'ACCEPT'
        option family 'ipv4'

config rule
        option name 'Allow-Ping'
        option src 'wan'
        option proto 'icmp'
        option icmp_type 'echo-request'
        option family 'ipv4'
        option target 'ACCEPT'

config rule
        option name 'Allow-IGMP'
        option src 'wan'
        option proto 'igmp'
        option family 'ipv4'
        option target 'ACCEPT'

config rule
        option name 'Allow-DHCPv6'
        option src 'wan'
        option proto 'udp'
        option dest_port '546'
        option family 'ipv6'
        option target 'ACCEPT'

config rule
        option name 'Allow-MLD'
        option src 'wan'
        option proto 'icmp'
        option src_ip 'fe80::/10'
        list icmp_type '130/0'
        list icmp_type '131/0'
        list icmp_type '132/0'
        list icmp_type '143/0'
        option family 'ipv6'
        option target 'ACCEPT'

config rule
        option name 'Allow-ICMPv6-Input'
        option src 'wan'
        option proto 'icmp'
        list icmp_type 'echo-request'
        list icmp_type 'echo-reply'
        list icmp_type 'destination-unreachable'
        list icmp_type 'packet-too-big'
        list icmp_type 'time-exceeded'
        list icmp_type 'bad-header'
        list icmp_type 'unknown-header-type'
        list icmp_type 'router-solicitation'
        list icmp_type 'neighbour-solicitation'
        list icmp_type 'router-advertisement'
        list icmp_type 'neighbour-advertisement'
        option limit '1000/sec'
        option family 'ipv6'
        option target 'ACCEPT'

config rule
        option name 'Allow-ICMPv6-Forward'
        option src 'wan'
        option dest '*'
        option proto 'icmp'
        list icmp_type 'echo-request'
        list icmp_type 'echo-reply'
        list icmp_type 'destination-unreachable'
        list icmp_type 'packet-too-big'
        list icmp_type 'time-exceeded'
        list icmp_type 'bad-header'
        list icmp_type 'unknown-header-type'
        option limit '1000/sec'
        option family 'ipv6'
        option target 'ACCEPT'

config rule
        option name 'Allow-IPSec-ESP'
        option src 'wan'
        option dest 'lan'
        option proto 'esp'
        option target 'ACCEPT'

config rule
        option name 'Allow-ISAKMP'
        option src 'wan'
        option dest 'lan'
        option dest_port '500'
        option proto 'udp'
        option target 'ACCEPT'

config zone
        option forward 'REJECT'
        option input 'REJECT'
        option output 'REJECT'
        option name 'dmz'
        list network 'dmz'

config forwarding
        option dest 'wan'
        option src 'dmz'

config forwarding
        option src 'lan'
        option dest 'dmz'

config zone
        option output 'ACCEPT'
        option input 'REJECT'
        option forward 'REJECT'
        option name 'guest'
        list network 'guest'

config forwarding
        option dest 'wan'
        option src 'guest'

config zone
        option input 'ACCEPT'
        option output 'ACCEPT'
        option name 'iot'
        list network 'iot'
        option forward 'REJECT'

config forwarding
        option src 'lan'
        option dest 'iot'

config zone
        option output 'ACCEPT'
        option name 'phone'
        list network 'phone'
        option input 'REJECT'
        option forward 'REJECT'

config forwarding
        option dest 'wan'
        option src 'phone'

config forwarding
        option src 'lan'
        option dest 'phone'

config rule
        option target 'ACCEPT'
        option name 'Guest DHCP'
        list proto 'udp'
        option src_port '68 546'
        option dest_port '67 547'
        option src 'guest'

config rule
        option name 'DMZ DHCP and DNS'
        option target 'ACCEPT'
        option dest_port '53 67 68 547'
        option src 'dmz'

config rule
        option name 'Phone DHCP and DNS'
        option target 'ACCEPT'
        option dest_port '53 67 68 547'
        option src 'phone'

config rule
        option name 'Allow-Inet-Homematic'
        list src_ip '192.168.50.10'
        option dest 'wan'
        option target 'ACCEPT'
        list proto 'tcp'
        option dest_port '80 123 443 8443'
        option src 'iot'

config rule
        option name 'Guest DNS'
        option dest_port '53'
        option target 'ACCEPT'
        list proto 'tcp'
        list proto 'udp'
        option src 'guest'

config rule
        option name 'Allow-Inet-Neato'
        list proto 'tcp'
        option src 'iot'
        list src_ip '192.168.50.118'
        option dest 'wan'
        option dest_port '443'
        option target 'ACCEPT'

Does anyone have an idea what this could be? I previously had a Fritzbox, on which the IPv6 assignment worked, so from the ISP everything should be fine.

2

In wan interface change option IPv6 to 1 (or manual in Luci) and restart it.

3

Thanks for your suggestion, I tried it, but it does not seem to have any effect. I also found some messages which might be related in the system log:

daemon.err odhcp6c[9875]: Failed to send RS (Network unreachable)
daemon.err odhcp6c[8055]: Failed to send SOLICIT message to ff02::1:2 (Network unreachable)
daemon.warn pppd[11544]: IPV6CP: timeout sending Config-Requests

Searching for this error messages did not bring up any results, which could be applied to my case. There was an issue with an interface which had net.ipv6.conf.***.disable_ipv6 = 1, but I've checked that already and all interfaces (except lan1, lan2, lan3 and lan4) hhave disable_ipv6 = 0, so WAN should work.

4

Try to turn off the Vigor for 10 minutes. Maybe your ISP is locking the identity of the device soliciting for the IPv6.

5

Try changing to:

option ip6ifaceid 'wan6'

Try:

wan

(It seems you edited some defaults here.)

6

@trendy Thanks for your suggestion, that seemed reasonable as I exchanged my previous router with the OpenWRT one just yesterday. I had everything disconnected (turned off) over night, but I still just get an IPv4 address.

@lleachii Yes, I changed to an alias as suggested in some posts here in the forums / wiki. I reverted the options back to default. Here's the current /etc/config/network:

config interface 'loopback'
        option device 'lo'
        option proto 'static'
        option ipaddr '127.0.0.1'
        option netmask '255.0.0.0'

config globals 'globals'
        option ula_prefix 'fd04:xxx::/48'

config device
        option name 'br-lan'
        option type 'bridge'
        list ports 'lan1'
        list ports 'lan2'
        list ports 'lan3'
        list ports 'lan4'

config interface 'lan'
        option proto 'static'
        option ipaddr '192.168.1.1'
        option netmask '255.255.255.0'
        option device 'br-lan.1'

config interface 'wan'
        option device 'wan'
        option proto 'pppoe'
        option username 'xxx'
        option password 'xxx'
        option ipv6 'auto'

config interface 'wan6'
        option proto 'dhcpv6'
        option reqaddress 'try'
        option reqprefix 'auto'
        option device 'wan'

config bridge-vlan
        option device 'br-lan'
        option vlan '1'
        list ports 'lan1:t*'
        list ports 'lan4:u*'

config bridge-vlan
        option device 'br-lan'
        option vlan '2'
        list ports 'lan1:t'

config bridge-vlan
        option device 'br-lan'
        option vlan '3'
        list ports 'lan1:t'

config bridge-vlan
        option device 'br-lan'
        option vlan '4'
        list ports 'lan1:t'

config bridge-vlan
        option device 'br-lan'
        option vlan '5'
        list ports 'lan1:t'
        list ports 'lan2:u*'
        list ports 'lan3:u*'

config interface 'dmz'
        option proto 'static'
        option device 'br-lan.2'
        option ipaddr '192.168.20.1'
        option netmask '255.255.255.0'

config interface 'guest'
        option proto 'static'
        option device 'br-lan.3'
        option ipaddr '192.168.30.1'
        option netmask '255.255.255.0'

config interface 'phone'
        option proto 'static'
        option device 'br-lan.4'
        option ipaddr '192.168.40.1'
        option netmask '255.255.255.0'

config interface 'iot'
        option proto 'static'
        option device 'br-lan.5'
        option ipaddr '192.168.50.1'
        option netmask '255.255.255.0'

config device
        option name 'wan'

config device
        option name 'pppoe-wan'
        option type 'tunnel'

I still do not receive an IPv6 address, the only change is that the UI shows:

Protocol: DHCPv6 client
MAC: xxx
RX: xxx
TX: xxx

on the WAN6 interface instead of just Protocol: Alias Interface (DHCPv6 client).

7

That's wrong, you confused it with ip6class.
And the @wan is correct way to set it up in pppoe.

1 Like
8

AAAH!

Now I understand what another poster meant in another thread. My bad, I indeed did confuse it.

Carry on!

1 Like
9

Some ISPs do not like auto:

#	option reqprefix 'auto'
	option reqprefix '56'

try setting to whatever you ISP is offering you.

1 Like
10

Thanks for your suggestion, 56 would be the correct prefix for Deutsche Telekom, but setting it instead of auto did not work either. I still do not get a IPv6 address.

11

As you have a quite complex VLAN setup, I would start small, first (e.g. on a spare router with OpenWrt).

IPv6 with DTAG has always been working fine for me (but I've switched to a different ISP now).

12

I found the issue, it was the Vigor 167 modem, not OpenWRT. There was a new Firmware update for the modem I overlooked, which "improved IPv6" supported. After updating the firmware of the modem OpenWRT obtains IPv6 just fine with the above settings. Thanks all for your ideas!

13

The modem shouldn't be involved in anything IPv6 at all, as you (according to your pasted config seem to-) terminate the PPPoE session on your OpenWrt router. Via PPPoE, the IPv4 and IPv6 endpoints are on the OpenWrt router, the modem itself doesn't have any (it's only the modem's webinterface, which tends to be exposed via IPv4).

14

I agree, theoretically it shouldn't do anything, except tagging with VLAN 7 (ISP requirement). But as it seems it does something it shouldn't do with FW 5.0.1. At least I found a few posts over in the OPNsense forums with the same issue (just with OPNsense instead of OpnWRT) and it is always solved by updating the FW of the Vigor 167.

15

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