The link local addresses of your endpoint and the Zen gateway come from IPV6CP, which is part of PPP - it has nothing to do with RA.
Indeed, I'm happy with that.
The only way your router's WAN interface will be auto-allocated a globally routable IPv6 address from the /64 ZEN allocate to you is if the router listens to RA and acts on the advertisement of the /64 with the flags indicating auto allocation (SLAAC) is permitted.
What I see at router startup with Wireshark is a RA from fe80::230:88ff:fe16:5eff (which is the Zen end of my PPP link):
Internet Control Message Protocol v6
Type: Router Advertisement (134)
Checksum: 0x38c1 [correct]
Cur hop limit: 64
0... .... = Managed address configuration: Not set
.1.. .... = Other configuration: Set
..0. .... = Home Agent: Not set
...0 0... = Prf (Default Router Preference): Medium (0)
.... .0.. = Proxy: Not set
.... ..0. = Reserved: 0
Router lifetime (s): 1200
Reachable time (ms): 0
Retrans timer (ms): 0
ICMPv6 Option (MTU : 1492)
Type: MTU (5)
Length: 1 (8 bytes)
ICMPv6 Option (Prefix information : 2a02:8011:d00b::/64)
Type: Prefix information (3)
Length: 4 (32 bytes)
Prefix Length: 64
1... .... = On-link flag(L): Set
.1.. .... = Autonomous address-configuration flag(A): Set
..0. .... = Router address flag(R): Not set
...0 0000 = Reserved: 0
Valid Lifetime: 18000
Preferred Lifetime: 1800
Prefix: 2a02:8011:d00b:: (2a02:8011:d00b::)
So my (limited) understanding is that the A flag is saying that SLAAC is allowed (and I'm not sure if the R flag needs to be set to make that route a default route).
However my TG582n appears to listen to RA (despite having DHCPv6 to be configured with listenra=disabled) to the extent of configuring the route, but doesn't get itself a SLAAC address on that network:
:ip rtlist proto=ipv6 expand disabled
Label Destination Interface Admin Oper Mtr Gateway
----- ----------- --------- ----- ---- --- -------
(Other routes redacted)
2a02:8011:d00b::/64 Internet UP UP 0
::/0 Internet UP UP 0 fe80::230:88ff:fe16:5eff
:ip iplist proto ipv6
Flags legend: [P]referred primar[Y] [R]oute [H]ost route d[E]precated [I]nvalid
[T]entative d[U]plicated [A]nycast auto[C]onf [D]ynamic [O]perational
Prefix Interface Type Flags
------ --------- ---- -----
2a02:8011:XXXX:0:9e97:26ff:fe77:4cfa/64 LocalNetwork Ethernet ...H.....CDO
2a02:8011:XXXX::/64 LocalNetwork Ethernet ..RH....A.DO
fe80::9e97:26ff:fe77:4cfa/64 LocalNetwork Ethernet ..RH......DO
fe80::9e97:26ff:fe77:4cfa/64 mobilebroadban.. Serial ..RH......DO
fe80::9e97:26ff:fe77:4cfa/64 Internet Serial ..RH......DO
::1/128 loop Internal ..RH......DO
fe80::1/64 loop Internal ..RH......DO
I'm presuming that listening to RA and getting the SLAAC address (and default route ?) should be happening before
DHCPv6 starts up. In that case, my looking at DHCPv6 config is too late and I should be looking at IPv6 config itself.
My suspicion is that the firmware I'm running isn't capable of doing what's needed. I've had no replies to a posting on the Zen forum asking if anyone else is using a TG582n on Zen's IPv6 trial, so maybe I'm on to a loser here.
Once again, thanks for your help with this.