default route via SLAAC not working ?

[Mike Tancsa]

Not sure if this is the client or the router (an LTE modem) or some
option on the FreeBSD client, but I am not getting the inet6 default
route installed when I pick up an IP6 addr at boot time.  Looking at the
pcap at the start, I see the following exchange


10:05:51.261641 a4:71:74:2b:c1:37 > 33:33:00:00:00:01, ethertype IPv6
(0x86dd), length 118: (hlim 255, next-header ICMPv6 (58) payload length:
64) fe80::a671:74ff:fe2b:c137 > ff02::1: [icmp6 sum ok] ICMP6, router
advertisement, length 64
        hop limit 64, Flags [managed, other stateful], pref high, router
lifetime 1800s, reachable time 0s, retrans time 0s
          prefix info option (3), length 32 (4):
2605:8d80:6e3:7365::/64, Flags [onlink, auto], valid time 7200s, pref.
time 3600s
            0x0000:  40c0 0000 1c20 0000 0e10 0000 0000 2605
            0x0010:  8d80 06e3 7365 0000 0000 0000 0000
          mtu option (5), length 8 (1):  1460
            0x0000:  0000 0000 05b4
          source link-address option (1), length 8 (1): a4:71:74:2b:c1:37
            0x0000:  a471 742b c137
10:05:51.926817 0c:5b:8f:27:9a:64 > 33:33:ff:27:9a:64, ethertype IPv6
(0x86dd), length 86: (hlim 255, next-header ICMPv6 (58) payload length:
32) :: > ff02::1:ff27:9a64: [icmp6 sum ok] ICMP6, neighbor solicitation,
length 32, who has 2605:8d80:6e3:7365:e5b:8fff:fe27:9a64
          unknown option (14), length 8 (1):
            0x0000:  0387 5e45 437d


And I have the IP6 addr assigned.

ue0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500
        ether 0c:5b:8f:27:9a:64
        hwaddr 0c:5b:8f:27:9a:64
        inet6 fe80::e5b:8fff:fe27:9a64%ue0 prefixlen 64 scopeid 0x7
        inet 192.168.8.100 netmask 0xffffff00 broadcast 192.168.8.255
        inet6 2605:8d80:6e3:7365:e5b:8fff:fe27:9a64 prefixlen 64 autoconf
        nd6 options=23<PERFORMNUD,ACCEPT_RTADV,AUTO_LINKLOCAL>


But no default route ? Is this something the client has to ask for ?
Unfortunately, on the little USB LTE modem, there are no options to
fiddle with ipv6 settings.


# netstat -anr -6
Routing tables

Internet6:
Destination                       Gateway                       Flags
  Netif Expire
::/96                             ::1                           UGRS
   lo0
::1                               link#6                        UH
   lo0
::ffff:0.0.0.0/96                 ::1                           UGRS
   lo0
2605:8d80:6e3:7365::/64           link#7                        U
   ue0
2605:8d80:6e3:7365:e5b:8fff:fe27:9a64 link#7                        UHS
       lo0
fe80::/10                         ::1                           UGRS
   lo0
fe80::%lo0/64                     link#6                        U
   lo0
fe80::1%lo0                       link#6                        UHS
   lo0
fe80::%ue0/64                     link#7                        U
   ue0
fe80::e5b:8fff:fe27:9a64%ue0      link#7                        UHS
   lo0
ff01::%lo0/32                     ::1                           U
   lo0
ff01::%ue0/32                     fe80::e5b:8fff:fe27:9a64%ue0  U
   ue0
ff02::/16                         ::1                           UGRS
   lo0
ff02::%lo0/32                     ::1                           U
   lo0
ff02::%ue0/32                     fe80::e5b:8fff:fe27:9a64%ue0  U
   ue0


-- 
-------------------
Mike Tancsa, tel +1 519 651 3400
Sentex Communications, mike at sentex.net
Providing Internet services since 1994 www.sentex.net
Cambridge, Ontario Canada   http://www.tancsa.com/