Thread border router - IPV6 DHCP problem

[Wojtek]

Hello everyone!

I've tried to send something from mesh to computer in my LAN via UDP and it works fine. Now I'm trying to implement CoAP with acknowlegements. The problem is that I'm unable to send something to inside of mesh. I want to do it in my LAN without routing to internet (no WAN connected). I'm using ASUS RT-AC51U router with IPv6 DHCP on. RPi gest its own IP with prefix specified in router but interface wpan0 (wpantund) not. Nodes in my mesh get ip with ULA-prefix specified in thread_border_router config file. I've tried propably every possible configuration on my router without any effect. What can i do about that to make it work? My border router works on v0.10.0 firmware.

Best regards, Wojciech Rzepecki

[Jørgen Holmefjord]

Hi,

What IPv6 prefix does the RPi BR get from your router? Note that the BR requires at least a /62 prefix to be able to further subnet the thread network, which require /64 prefix address.

Please have a look at this thread.

Best regards,

Jørgen

[Wojtek]

Thanks for fast response! I've set fd00:300:1234:5678:: prefix on my router. I've tried to pass prefix of /62 and /64 length but it didn't work at all. Propably I have the same issue that was described in thread that you send me. I will try do something with OpenWRT.

[Wojtek]

I've installed OpenWRT on other router. I'm unable to make it work. Could you describe what options i have to choose in openwrt configuration? I've tried many configurations but i'm stuck for now.

Best Regards, Wojciech Rzepecki

[Wojtek]

I solved the problem with a Jørgens little help. To make a proper DHCPv6 server OpenWRT is needed. Router must have assigned proper static IP with prefix shorter than /63. DHCP server must be configured in relay mode. In my case I couldn't have prefix from WAN. I had to configure it in this way to make bidirectional communication with mesh inside LAN.

Example of OpenWRT configuration on router:

config interface lan
        option ifname   eth1
        option proto    static
        option ip6addr  2001:db80::2/48 
        option ip6gw    2001:db80::1      
        option ip6prefix 2001:db80:1::/48 
        option dns      2001:db80::1      # DNS server

Best regards, Wojciech Rzepecki

[Carry Irving]

Hi, Could you tell me what does it mean as you say "DHCP server must be configured in relay mode". How can I configure my Router for that? I encountered the problem which you have met before. I'm using ASUS RT-AC1900P router with IPv6 DHCP on. RPi gest its own IP with prefix specified in router but interface wpan0 (wpantund) not. I have configured the Router properly, the static IPv6 with /62 prefix. But RPI seems to get the prefix failed and my Thread nodes don't have an IPv6 address created using /62 prefix.