Hello, I need a help to configure ipv6 in openwrt, I checked the openwrt wiki but I found it very confusing and I could not solve my problem
well, let's go
My Internet Provider (Vivo speedy) gives me a prefix 2804: xxx: xxxx: xxx :: dynamic, I make the connection openwrt to the router in nat mode the router works normally and can get ipv6 connectivity but I can not configure ipv6 on my internal network
What is the best way to do this confuguration?
Thanks for any help

Hi Gustavo,

Are you able to switch your ISP's modem to bridge mode ? If so, it will bring a much easier start and better end results for the IPv6 setup. Likely, the default OpenWrt IPv6 config would work above it.

I live in Brazil too and heard about some Vivo (previously GVT) xDSL modems that could be unlocked to allow switching to bridge mode.

If this is not possible in your case and you need to cascade the two routers, then I'd recommend the relay mode (NDP proxy) for sharing the public /64 prefix with the downstream LAN.

PS: I'm a Vivo broadband customer too in Florianópolis. But since my internet plan is only 15Mbps with no TV subscription, I chose to use a generic D-Link ADSL modem in place of whatever piece of crap Vivo would bring to me. Then of course the bridge mode is available and is used to allow the OpenWrt router to fully manage the PPPoE tunnel and get the delegated IPv6 prefix from it.

Hi andre thanks for replying, unfortunately not this modem is crap, I can configure bridge but if I disconnect and religo it returns to the default configuration, I understand maybe it is better to consider buying another modem but at the moment could you help me with the NDP configuration? Preferably by Luci

Hi Gustavo,

As several users have reported, NDP proxy is not working out of the box on OpenWrt. There are some bugs in odhcpd that prevent it. However, I wrote down the steps to make it work by doing some tweaks in the configuration. It's on this post: https://forum.openwrt.org/viewtopic.php … 68#p346368 .

I went through it step-by-step today, starting from a Chaos Calmer 15.05.1 stock configuration and confirmed it worked.

Thanks AndreL but I still could not make the configuration informed but I'm using the LEDE Project and when I tried to download the old version of odhcpd reported architecture error even downloading the version of my ar71xx router, so I decided to follow the rest of the tutorial and the result was the Even get ipv6 connectivity through the router but can not distribute to the network

Ifconfig machine

Enp6s0: flags = 4163 <UP, BROADCAST, RUNNING, MULTICAST> mtu 1500
        Inet 192.168.1.177 netmask 255.255.255.0 broadcast 192.168.1.255
        Inet6 fe80 :: b6e8: e235: e9f8: fc09 prefixlen 64 scopeid 0x20 <link>
        Ether 5c: f9: dd: 48: 12: 87 txqueuelen 1000 (Ethernet)
        RX packets 40266 bytes 39106937 (39.1 MB)
        RX errors 0 dropped 1 overruns 0 frame 0
        TX packets 36078 bytes 8035334 (8.0 MB)
        TX errors 0 dropped 0 overruns 0 carrier 0 collisions 0

Ping router ping6 google.com
PING google.com (2800: 3f0: 4001: 803 :: 200e): 56 data bytes
64 bytes from 2800: 3f0: 4001: 803 :: 200e: seq = 0 ttl = 50 time = 149,846 ms
64 bytes from 2800: 3f0: 4001: 803 :: 200e: seq = 1 ttl = 50 time = 149,361 ms
64 bytes from 2800: 3f0: 4001: 803 :: 200e: seq = 2 ttl = 50 time = 149,716 ms
^ C

Ping machine

Ping6 google.com
PING google.com (2800: 3f0: 4001: 806 :: 200e (2800: 3f0: 4001: 806 :: 200e)) 56 data bytes
Ping: sendmsg: The network is out of range
Ping: sendmsg: The network is out of range
Ping: sendmsg: The network is out of range
^ C

I think there may be some additional configuration that I can do in the modem if you know please let me know

imgur.com/5VqouB3

Hi Gustavo,

I currently have no experience with LEDE, but I'd expect that a newer odhcpd version would have the bugs fixed and would work out of the box. I'm surprised you tried it with LEDE and got nothing.

From your modem's screen shot, there is no useful option that could facilitate the config. Essentialy, the ISP box is implementing both modem and router functions. But since you want LEDE to act as the router, the ISP device would really do better job if switched to bridge mode.

Your machine's ifconfig does not show the IPv6 addresses. Perhaps your LEDE router is now missing the odhcpd package because of uninstallation. Try installing it again from the normal LEDE repositories:
opkg update
opkg install odhcpd

This page https://lede-project.org/docs/user-guid … figuration says

This is exactly what you need if cannot switch the modem to bridge. I hope other LEDE users can tell you if it works as stated above.

I have a GVT/Vivo link and IPv6 isn't working in downstream routers.
Using IPv4 everyting is work fine.
My hope is to make IPv6 work as well as IPv4.

Vivo router is a MitraStar DSL-2401HN-T1C-GV with firmware version BR_GV_114WQR0b13.
All machines (including my first level router) get a working IPv6 from Vivo router.

My first level router is a tplink wrt740n with LEDE 17.01.2
I able todo ping6 google.com inside the router, but any machines (including my second level router) in lan can't work.

My second level router is a tplink wr1043nd with LEDE 17.01.2.

I activated the luci web interface on lan all the options for relay. The web interface has no option to indicate which interface is the master for the relay, so I manually edited /etc/config/dhcp to add 'option master 1' on the wan interface. But it still does not work.

Hi murilopontes,

Can this MiraStar modem/router be switched to bridge mode so to run the PPPoE session from LEDE ? That would make the configuration much easier and more flexible on the downstream router, since the ISP is likely providing nothing but a single /64 prefix for LAN.

Next question is if you really need the second tp-link (wr1043nd) as a router, to isolate networks or something. Maybe a different setup, like one tp-link as router (doing IPv6) and the other(s) as simple access points or WDS bridges would suffice.

MiraStar is a blackbox no easyway change configuration. This problem of providing the ISP with only one block for LAN seems very common in the research I did. Openwrt treats this as an exception when in fact it should be the default case, most ISPs adopt this practice.

The second level tp-link (wr1043) as expanding the network, WDS is not possible due build, the wan connection to first level router is wired. The IPv4 part of this setup works perfect using NAT. I tried using NAT with ipv6, recompiled openwrt 15.05.1 from sources to enable IPv6 NAT modules, but it also did not work  (The result was the same only works ping6 inside the first level router and the other machines that are direct clients of the MiraStar LAN).

I was seeing a brouter scheme, to keep ipv4 routed and bridge to ipv6, but support for that has been removed since openwrt 15.05.

Using the following configuration (in both first and second level routers), the first level and second level routers get ipv6 address, ping6 google.com working only inside of first router, machines on lan not work.

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

config dhcp 'wan6'
    option dhcpv6 'relay'
    option ra 'relay'
    option ndp 'relay'
    option master '1'

config dhcp 'lan'
    option interface 'lan'
    option start '100'
    option limit '150'
    option leasetime '12h'
    option ra 'relay'
    option dhcpv6 'relay'
    option ndp 'relay'

From MiraStar status page
Delegated prefix: 2804:7f7:dc80:79dc::
IPv6 Link-Local - LAN: fe80::9a97:d1ff:fe16:2130/10
IPv6 Global - WAN: 2804:7f7:d42f:398f:9a97:d1ff:fe16:2130/64
default GW: fe80::d2f0:dbff:fe62:5000
primary DNS : 2804:7f4:2002:1005::98
secondary DNS : 2804:7f4:2002:1005::99

From First level router WAN interface
          inet6 addr: fe80::ea94:f6ff:fe9d:f42/64 Scope:Link
          inet6 addr: 2804:7f7:dc80:79dc:ea94:f6ff:fe9d:f42/64 Scope:Global
          inet6 addr: 2804:7f7:dc80:40d5:ea94:f6ff:fe9d:f42/64 Scope:Global
ping6 google.com work inside this router
any machine on lan include the second level router and notebook1 are able to get ipv6 address, but ping6 fail

From Second level router WAN
          inet6 addr: 2804:7f7:dc80:79dc:fa1a:67ff:fea4:dc3c/64 Scope:Global
          inet6 addr: fe80::fa1a:67ff:fea4:dc3c/64 Scope:Link
ping6 google.com fail inside this router, just like any other client machine on the first-level router LAN.

Actually, it depends on where you are. In North America, I think it is more common for ISPs to give out more than a /64.

If you only have one /64 from your ISP, you will need to put downstream routers in bridge mode (or use the relay option of odhcpd).

(Last edited by cvmiller on 23 Jun 2017, 16:58)

NDP proxy seems to me the most appropriate solution to share a /64 prefix between multiple subnets if there's a reason not to bridge them.

I have NDP proxy working in OpenWrt with lots of workarounds (see https://forum.openwrt.org/viewtopic.php … #p346368), but I don't know about the situation in LEDE.

If I had a similar setup, I'd use the second level router as a wired access point, avoiding the double (or triple?) NAT for v4 and any extra difficulty on sharing the /64 for v6 on that router. Then try to solve the IPv6 issues between the ISP box and the first router.

Maybe the MiraStar blackbox can be unlocked to bridge mode with some research on hacks for it or can be replaced by another xDSL modem that have such option available.