Possible "bug" in IPv6/Autoconfiguration?

Question

Hello,
I found some "interesting" behaviour of a 2010 Mac Book Pro connected via Wifi to the internet while using IPv6:
Just a few infos about my setup:
I run a FreeBSD Firewall on 8.2-Release connected to the internet via a 100MBit/s cablemodem.
Wifi is handled by a Zyxel NWA3160 and they're interconnected via a HP1810G Switch.
So in the end you have:
Wifi Client <-(wifi)-> Zyxel AP <-> HP Switch <-> FreeBSD Firewall <-> cablemodem <-> outer rim
The Router runs "radvd" to advertise the subnet for autoconfiguration.
So what happens?
When I connect the MBP to the wifi network it get's an ip address,subnet,dns and router assigned via DHCP(v4) (everything ok).
It also checks for the router advertisement and autoconfigures it's ip address based on the provided subnet as well as the default router (V6).
Till this point everything is OK.
A few minutes later the next router advertisement takes place, and the system deletes the "old" route and adds the "new" route in two steps at the same time:
got message of size 152 on Mon May 30 11:18:54 2011
RTM_DELETE: Delete Route: len 152, pid: 14, seq 1097, errno 0, flags:<GATEWAY,DONE,STATIC,PRCLONING,CONDEMNED>
locks:  inits:
sockaddrs: <DST,GATEWAY,NETMASK>
:: fe80::rout.ersa.ddre.ss00%en1 default
got message of size 196 on Mon May 30 11:18:54 2011
RTM_ADD: Add Route: len 196, pid: 14, seq 1098, errno 0, flags:<UP,GATEWAY,DONE,STATIC>
locks:  inits:
sockaddrs: <DST,GATEWAY,NETMASK,IFP>
:: fe80::rout.ersa.ddre.ss00%en1 :: en1
Still OK, and I can see the RA as well as the Neighbour Solicitation take place in Wireshark.
But about 40 to 50 seconds later I can see this in the routing monitor:
got message of size 200 on Mon May 30 11:19:39 2011
RTM_DELETE: Delete Route: len 200, pid: 0, seq 0, errno 0, flags:<GATEWAY,DONE,STATIC,PRCLONING,CONDEMNED>
locks:  inits:
sockaddrs: <DST,GATEWAY,NETMASK,IFP,IFA>
:: fe80::rout.ersa.ddre.ss00%en1 default en1:ma.co.fe.n1.aa.bb  fe80::prot:ectt:hein:nocc:ent0%en1
and the route is deleted.
But there wasn't any packet on the wire. Just nothing.
So how come the box deletes the default route and doesn't add it again.
This is weird. I checked for serveral timeouts, tried to find something in the logs and so on but I couldn't find anything.
Anyone any hints?
KR,
Gisikon

Answer 1

Update after completing Microsoft support call.
Was connected to senior Microsoft tech support rep via a paid support call on this matter. After a number of remote sessions and several escalations Microsoft arrived at their explanation as to why this is an icloud problem. Microsoft explained that apple has a closed solution based on imap or something like that and that the icloud creates a separate pst file that it uses to move and store the outlook contact records why the icloud software is active. The icloud special pst is stored locally on my PC but separate from the normal PST. Per Microsoft this is the root cause of the problem and its upto apple to fix it.