GUA address not being assigned to wpan0

[roshanshajijohn]

Setup Details

• Raspberry pi os : Raspbian GNU/Linux 11 (bullseye) 32 bit

• ot-br-posix commit id used : https://github.com/openthread/ot-br-posix/tree/b574b6c2a4ea2ea265f87b908c8ef3f673b27f7f

• modifications done to examples/platforms/raspbian/default NAT64=1 DNS64=0 DHCPV6_PD=0 DHCPV6_PD_REF=1 NETWORK_MANAGER=0 BACKBONE_ROUTER=1 BORDER_ROUTING=1 WEB_GUI=0 REST_API=0

• ran sudo ./script/bootstrap and sudo INFRA_IF_NAME=eth0 ./script/setup and sudo reboot

• A thread network was established following https://openthread.io/codelabs/openthread-border-router#2, and a Full Thread Device (FTD) was successfully connected to the network.

• But no GUA assigned to wpan0 interface

• The following are logs from various commands :

pi@raspberrypi:~/ot-br-posix $ ifconfig
eth0: flags=4163<UP,BROADCAST,RUNNING,MULTICAST>  mtu 1500
        inet 192.168.29.186  netmask 255.255.255.0  broadcast 192.168.29.255
        inet6 fe80::ba27:ebff:fe0b:b76  prefixlen 64  scopeid 0x20<link>
        inet6 2405:<private>:<private>:<private>::b76  prefixlen 64  scopeid 0x0<global>
        ether b8:27:eb:0b:0b:76  txqueuelen 1000  (Ethernet)
        RX packets 4794  bytes 436863 (426.6 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 1442  bytes 178279 (174.1 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

lo: flags=73<UP,LOOPBACK,RUNNING>  mtu 65536
        inet 127.0.0.1  netmask 255.0.0.0
        inet6 ::1  prefixlen 128  scopeid 0x10<host>
        loop  txqueuelen 1000  (Local Loopback)
        RX packets 53  bytes 10965 (10.7 KiB)
        RX errors 0  dropped 0  overruns 0  frame 0
        TX packets 53  bytes 10965 (10.7 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

wpan0: flags=4305<UP,POINTOPOINT,RUNNING,NOARP,MULTICAST>  mtu 1280
        inet6 fd4e:3715:25a7:f4f7:0:ff:fe00:fc11  prefixlen 64  scopeid 0x0<global>
        inet6 fd4e:3715:25a7:f4f7:0:ff:fe00:fc00  prefixlen 64  scopeid 0x0<global>
        inet6 fd6c:5cc6:beff:1:fcc2:d471:731d:bcf8  prefixlen 64  scopeid 0x0<global>
        inet6 fd4e:3715:25a7:f4f7:dc84:c33f:d3c0:bb7f  prefixlen 64  scopeid 0x0<global>
        inet6 fe80::58af:3b1f:3a09:81ec  prefixlen 64  scopeid 0x20<link>
        inet6 fd4e:3715:25a7:f4f7:0:ff:fe00:fc10  prefixlen 64  scopeid 0x0<global>
        inet6 fd4e:3715:25a7:f4f7:0:ff:fe00:fc38  prefixlen 64  scopeid 0x0<global>
        inet6 fd4e:3715:25a7:f4f7:0:ff:fe00:3c00  prefixlen 64  scopeid 0x0<global>
        unspec 00-00-00-00-00-00-00-00-00-00-00-00-00-00-00-00  txqueuelen 500  (UNSPEC)
        RX packets 442  bytes 40715 (39.7 KiB)
        RX errors 0  dropped 2  overruns 0  frame 0
        TX packets 16  bytes 2696 (2.6 KiB)
        TX errors 0  dropped 0 overruns 0  carrier 0  collisions 0

pi@raspberrypi:~/ot-br-posix $ sysctl net.ipv6.conf.all.forwarding
net.ipv6.conf.all.forwarding = 1
pi@raspberrypi:~/ot-br-posix $ sysctl net.ipv4.ip_forward
net.ipv4.ip_forward = 1
pi@raspberrypi:~/ot-br-posix $ sysctl net.ipv6.conf.eth0.accept_ra
net.ipv6.conf.eth0.accept_ra = 2
pi@raspberrypi:~/ot-br-posix $ sysctl net.ipv6.conf.eth0.accept_ra_rt_info_max_plen
net.ipv6.conf.eth0.accept_ra_rt_info_max_plen = 64

pi@raspberrypi:~/ot-br-posix $ ip -6 route
::1 dev lo proto kernel metric 256 pref medium
2405:<private>::/64 dev eth0 proto kernel metric 256 expires 7467sec pref medium
fd4e:3715:25a7:f4f7::/64 dev wpan0 proto kernel metric 256 pref medium
fd6c:5cc6:beff:1::/64 dev wpan0 proto kernel metric 256 pref medium
fe80::/64 dev eth0 proto kernel metric 256 pref medium
fe80::/64 dev wpan0 proto kernel metric 256 pref medium
default via fe80::f2ed:b8ff:fe47:f5a8 dev eth0 proto ra metric 1024 expires 3582sec hoplimit 64 pref high

pi@raspberrypi:~/ot-br-posix $ sudo ip6tables -vL
Chain INPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

Chain FORWARD (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination
    1    56 OTBR_FORWARD_INGRESS  all      any    wpan0   anywhere             anywhere

Chain OUTPUT (policy ACCEPT 0 packets, 0 bytes)
 pkts bytes target     prot opt in     out     source               destination

Chain OTBR_FORWARD_INGRESS (1 references)
 pkts bytes target     prot opt in     out     source               destination
    0     0 DROP       all      wpan0  any     anywhere             anywhere             PKTTYPE = unicast
    0     0 DROP       all      any    any     anywhere             anywhere             match-set otbr-ingress-deny-src src
    1    56 ACCEPT     all      any    any     anywhere             anywhere             match-set otbr-ingress-allow-dst dst
    0     0 DROP       all      any    any     anywhere             anywhere             PKTTYPE = unicast
    0     0 ACCEPT     all      any    any     anywhere             anywhere

• RA's seen in tcpdump as below. Pls note the prefixes have been marked private and intentionally made zeros.

pi@raspberrypi:~/ot-br-posix $ sudo tcpdump -vv -i eth0 icmp6 and 'ip6[40] == 134 or ip6[40] == 133'
tcpdump: listening on eth0, link-type EN10MB (Ethernet), snapshot length 262144 bytes
21:43:10.579436 IP6 (flowlabel 0xd12ef, hlim 255, next-header ICMPv6 (58) payload length: 32) raspberrypi.local > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 32
        hop limit 0, Flags [other stateful, ipv6 only], pref medium, router lifetime 0s, reachable time 0ms, retrans timer 0ms
          route info option (24), length 16 (2):  fd6c:5cc6:beff:1::/64, pref=medium, lifetime=1800s
            0x0000:  4000 0000 0708 fd6c 5cc6 beff 0001
21:43:19.989836 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 88) fe80::f2ed:b8ff:fe47:f5a8 > ip6-allnodes: [icmp6 sum ok] ICMP6, router advertisement, length 88
        hop limit 64, Flags [other stateful], pref high, router lifetime 3600s, reachable time 0ms, retrans timer 0ms
          prefix info option (3), length 32 (4): 2405:<private>::/64, Flags [onlink, auto], valid time 7485s, pref. time 7485s
            0x0000:  40c0 0000 1d3d 0000 1d3d 0000 0000 2405
            0x0010:  0000 0000 0000 0000 0000 0000 0000
          rdnss option (25), length 24 (3):  lifetime 7485s, addr: reliance.reliance
            0x0000:  0000 0000 1d3d 2405 0000 0000 0000 0000
            0x0010:  0000 0000 0000
          mtu option (5), length 8 (1):  1500
            0x0000:  0000 0000 05dc
          source link-address option (1), length 8 (1): f0:ed:b8:47:f5:a8
            0x0000:  f0ed b847 f5a8

• output of dhcpcd.conf

noipv6rs # disable router solicitation
interface eth0
  iaid 1
  ia_pd 2/::/64 -
release
# Disable Router Solicitations (RS) again, specifically for eth0.
# This ensures that accept_ra is prevented from being set to 0, allowing
# the interface to accepting Router Advertisements and configuring IPv6
# based on them. The exact reason for requiring 'noipv6rs' twice
# is not fully understood but has been observed to be necessary through
# experimentation.
noipv6rs
noipv6rs

• output of journalctl -xe -u otbr-agent -f

Feb 25 19:59:29 raspberrypi otbr-agent[1255]: 00:03:58.179 [I] MeshForwarder-: Sent IPv6 HopOpts msg, len:86, chksum:0000, ecn:no, to:0xffff, sec:yes, prio:net
Feb 25 19:59:29 raspberrypi otbr-agent[1255]: 00:03:58.179 [I] MeshForwarder-:     src:[fd4e:3715:25a7:f4f7:0:ff:fe00:3c00]
Feb 25 19:59:29 raspberrypi otbr-agent[1255]: 00:03:58.179 [I] MeshForwarder-:     dst:[ff03:0:0:0:0:0:0:2]
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:58.780 [I] RoutingManager: Received RA from fe80:0:0:0:f2ed:b8ff:fe47:f5a8 on infra netif 2
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:58.780 [I] RoutingManager: - RA Header - flags - M:0 O:1 S:0
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:58.780 [I] RoutingManager: - RA Header - default route - lifetime:3600
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:58.781 [I] RoutingManager: - RA Header - default route - lifetime:3600
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:58.781 [I] RoutingManager: - PIO 2405:<private>::/64 (valid:7485, preferred:7485)
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:59.136 [I] Mle-----------: Send Advertisement (ff02:0:0:0:0:0:0:1)
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:59.156 [I] MeshForwarder-: Sent IPv6 UDP msg, len:90, chksum:e02f, ecn:no, to:0xffff, sec:no, prio:net
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:59.156 [I] MeshForwarder-:     src:[fe80:0:0:0:58af:3b1f:3a09:81ec]:19788
Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:59.156 [I] MeshForwarder-:     dst:[ff02:0:0:0:0:0:0:1]:19788

[jwhui]

Is there a DHCPv6 Server providing IPv6 Prefixes?

From the otbr-agent log, it appears that the upstream router is not advertising stateful configuration (M flag is 0):

Feb 25 19:59:30 raspberrypi otbr-agent[1255]: 00:03:58.780 [I] RoutingManager: - RA Header - flags - M:0 O:1 S:0