IPv6 address deprection problem

Hi,

For some reason, the IPv6 addresses of the computers on my local network
keep being marked as deprecated (with loss of global IPv6 connectivity,
since no other non-local address is being used). I have tried to track
down the problem, but as far as I can see, this deprecation should not
happen since the preferred address lifetime is being reset on a regular
basis by router advertisements. Do you have an idea of what could be
happening?

Here are the details of the local network:
* 1 Windows 2008 server
* 1 Windows Vista SP1 client
* 1 router (based on FreeBSD 7), with IPv4 and IPv6 connectivity.
Both the Windows server and client exhibit the address deprecation
problem.
Transitional (6to4, ISATAP, Teredo) network adapters are disabled.
IPv6 addresses are assigned by stateless autoconfiguration, plus
statless DHCPv6 for assigning DNS server addresses. AFAIK, there is
nothing atypical with this setup.
Running "ipconfig /renew6" does not fix the problem. It does reset the
preferred lifetime, but the address stay deprecated.

Here is some netsh data captured when the problem was happening:

====

PS C:\Users\Lionel> netsh int ipv6 show addresses level=verbose

Address ::1 Parameters
---------------------------------------------------------
Interface Luid : Loopback Pseudo-Interface 1
Scope Id : 0.0
Valid Lifetime : infinite
Preferred Lifetime : infinite
DAD State : Preferred
Address Type : Other

Address 2001:660:f080:21:216:76ff:fed0:5a4f Parameters
---------------------------------------------------------
Interface Luid : Local Area Connection
Scope Id : 0.0
Valid Lifetime : 29d23h58m42s
Preferred Lifetime : 6d23h58m42s
DAD State : Deprecated
Address Type : Public

Address 2001:660:f080:21:c02e:2054:6baa:3af9 Parameters
---------------------------------------------------------
Interface Luid : Local Area Connection
Scope Id : 0.0
Valid Lifetime : 6d11h42m11s
Preferred Lifetime : 6d11h42m11s
DAD State : Deprecated
Address Type : Temporary

Address fe80::216:76ff:fed0:5a4f%10 Parameters
---------------------------------------------------------
Interface Luid : Local Area Connection
Scope Id : 0.10
Valid Lifetime : infinite
Preferred Lifetime : infinite
DAD State : Preferred
Address Type : Other

PS C:\Users\Lionel> netsh int ipv6 show interface level=verbose

Interface Loopback Pseudo-Interface 1 Parameters
----------------------------------------------
IfLuid : loopback_0
IfIndex : 1
Compartment Id : 1
State : connected
Metric : 50
Link MTU : 4294967295 bytes
Reachable Time : 43500 ms
Base Reachable Time : 30000 ms
Retransmission Interval : 1000 ms
DAD Transmits : 0
Site Prefix Length : 64
Site Id : 1
Forwarding : disabled
Advertising : disabled
Neighbor Discovery : disabled
Neighbor Unreachability Detecion : disabled
Router Discovery : enabled
Managed Address Configuration : disabled
Other Stateful Configuration : disabled
Weak Host Sends : disabled
Weak Host Receives : disabled
Use Automatic Metric : enabled
Ignore Default routes : disabled

Interface Local Area Connection Parameters
----------------------------------------------
IfLuid : ethernet_6
IfIndex : 10
Compartment Id : 1
State : connected
Metric : 10
Link MTU : 1500 bytes
Reachable Time : 39000 ms
Base Reachable Time : 30000 ms
Retransmission Interval : 1000 ms
DAD Transmits : 1
Site Prefix Length : 64
Site Id : 1
Forwarding : disabled
Advertising : disabled
Neighbor Discovery : enabled
Neighbor Unreachability Detecion : enabled
Router Discovery : enabled
Managed Address Configuration : disabled
Other Stateful Configuration : enabled
Weak Host Sends : disabled
Weak Host Receives : disabled
Use Automatic Metric : enabled
Ignore Default routes : disabled

====


Capturing ICMPv6 packets on the router show periodic router
advertisement messages, which should keep the addresses from being
deprecated. Here is a typical capture:

====
11:07:09.463637 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 56) fe80::215:17ff:fe62:8316 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 56
hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
prefix info option (3), length 32 (4): 2001:660:f080:21::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 0660 f080 0021 0000 0000 0000 0000
11:13:02.468979 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 56) fe80::215:17ff:fe62:8316 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 56
hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
prefix info option (3), length 32 (4): 2001:660:f080:21::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 0660 f080 0021 0000 0000 0000 0000
11:18:25.619714 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) 2001:660:f080:21:b983:416c:6ff9:de6b > ff02::1:ff00:1: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2001:660:f080:21::1
source link-address option (1), length 8 (1): 00:0f:b0:66:11:e6
0x0000: 000f b066 11e6
11:18:25.619880 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) 2001:660:f080:21::1 > 2001:660:f080:21:b983:416c:6ff9:de6b: [icmp6 sum ok] ICMP6, neighbor advertisement, length 32, tgt is 2001:660:f080:21::1, Flags [router, solicited, override]
destination link-address option (2), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
11:18:30.619851 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) 2001:660:f080:21::1 > 2001:660:f080:21:b983:416c:6ff9:de6b: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2001:660:f080:21:b983:416c:6ff9:de6b
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
11:18:30.620194 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) 2001:660:f080:21:b983:416c:6ff9:de6b > 2001:660:f080:21::1: [icmp6 sum ok] ICMP6, neighbor advertisement, length 32, tgt is 2001:660:f080:21:b983:416c:6ff9:de6b, Flags [solicited, override]
destination link-address option (2), length 8 (1): 00:0f:b0:66:11:e6
0x0000: 000f b066 11e6
11:21:59.472104 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 56) fe80::215:17ff:fe62:8316 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 56
hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
prefix info option (3), length 32 (4): 2001:660:f080:21::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 0660 f080 0021 0000 0000 0000 0000
11:25:44.473515 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 56) fe80::215:17ff:fe62:8316 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 56
hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
prefix info option (3), length 32 (4): 2001:660:f080:21::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 0660 f080 0021 0000 0000 0000 0000
11:33:25.480505 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 56) fe80::215:17ff:fe62:8316 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 56
hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
prefix info option (3), length 32 (4): 2001:660:f080:21::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 0660 f080 0021 0000 0000 0000 0000
11:43:04.489248 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 56) fe80::215:17ff:fe62:8316 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 56
hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
prefix info option (3), length 32 (4): 2001:660:f080:21::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 0660 f080 0021 0000 0000 0000 0000


====


and here is a capture during "ipconfig /renew6":

====
12:34:53.605663 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 16) fe80::216:76ff:fed0:5a4f > ff02::2: [icmp6 sum ok] ICMP6, router solicitation, length 16
source link-address option (1), length 8 (1): 00:16:76:d0:5a:4f
0x0000: 0016 76d0 5a4f
12:34:53.655333 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 56) fe80::215:17ff:fe62:8316 > ff02::1: [icmp6 sum ok] ICMP6, router advertisement, length 56
hop limit 64, Flags [other stateful], pref medium, router lifetime 1800s, reachable time 0s, retrans time 0s
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
prefix info option (3), length 32 (4): 2001:660:f080:21::/64, Flags [onlink, auto], valid time 2592000s, pref. time 604800s
0x0000: 40c0 0027 8d00 0009 3a80 0000 0000 2001
0x0010: 0660 f080 0021 0000 0000 0000 0000
12:34:55.584323 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) 2001:660:f080:21::1 > 2001:660:f080:21:216:76ff:fed0:5a4f: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2001:660:f080:21:216:76ff:fed0:5a4f
source link-address option (1), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
12:34:55.584526 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) 2001:660:f080:21:c02e:2054:6baa:3af9 > ff02::1:ff00:1: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has 2001:660:f080:21::1
source link-address option (1), length 8 (1): 00:16:76:d0:5a:4f
0x0000: 0016 76d0 5a4f
12:34:55.584616 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) 2001:660:f080:21::1 > 2001:660:f080:21:c02e:2054:6baa:3af9: [icmp6 sum ok] ICMP6, neighbor advertisement, length 32, tgt is 2001:660:f080:21::1, Flags [router, solicited, override]
destination link-address option (2), length 8 (1): 00:15:17:62:83:16
0x0000: 0015 1762 8316
12:34:55.584768 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) 2001:660:f080:21:216:76ff:fed0:5a4f > 2001:660:f080:21::1: [icmp6 sum ok] ICMP6, neighbor advertisement, length 32, tgt is 2001:660:f080:21:216:76ff:fed0:5a4f, Flags [solicited, override]
destination link-address option (2), length 8 (1): 00:16:76:d0:5a:4f
0x0000: 0016 76d0 5a4f
12:34:55.664973 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 32) fe80::216:76ff:fed0:5a4f > fe80::215:17ff:fe62:8316: [icmp6 sum ok] ICMP6, neighbor solicitation, length 32, who has fe80::215:17ff:fe62:8316
source link-address option (1), length 8 (1): 00:16:76:d0:5a:4f
0x0000: 0016 76d0 5a4f
12:34:55.665037 IP6 (hlim 255, next-header ICMPv6 (58) payload length: 24) fe80::215:17ff:fe62:8316 > fe80::216:76ff:fed0:5a4f: [icmp6 sum ok] ICMP6, neighbor advertisement, length 24, tgt is fe80::215:17ff:fe62:8316, Flags [router, solicited]

====


Anticipated thanks,

--
Lionel

So, I am about to setup a very similar environment, but have not yet made it
to setting up rtadvd on FreeBSD 7.

So, the only advice I have at the moment (until I get a bit further) is to
check out the following Technet. and FreeBSD articles:
http://technet.microsoft.com/en-us/m.../cc137983.aspx
http://www.freebsd.org/doc/en_US.ISO...HBOR-DISCOVERY

and to ask questions...

1) Do you have any Firewall or AV software installed on the windows pc's ?
If yes, many do not yet properly deal with IPV6. Try uninstalling since
disable "just doesn't work" for most firewalls even know it should.

2) Post your rtadvd.conf file from FreeBSD7
3) Post your dhcp config file (are you using ISC or WIDE version ?)
4) Get a trace from the Windows PC (rather than tcpdump from FreeBSD) {This
can help dispell firewall issues as well.} I recommend wireshark or MS
Netmon 3.1 (both free) for windows.

Good Luck, and sorry I could not give you a better answer yet, but at the
moment you are ahead of me on IPv6 test config.

--Dave

On 2008-05-22, GadgetDave <(E-Mail Removed)> wrote:
> 1) Do you have any Firewall or AV software installed on the windows pc's ?
> If yes, many do not yet properly deal with IPV6. Try uninstalling since
> disable "just doesn't work" for most firewalls even know it should.

No AV on the server, and no third-party firewall. Anyway, the RA
packets are not blocked since the preferred lifetime is reset.

> 2) Post your rtadvd.conf file from FreeBSD7

em0:\
:raflags="o":

> 3) Post your dhcp config file (are you using ISC or WIDE version ?)

I use dhcp6s, here is the dhcp6s.conf (IPv4 DHCP is irrelevant here).

option domain-name-servers 2001:660:f080:21::1;
option ntp-servers 2001:660:f080:21::1;
option refreshtime 3600;

I have had my IPv6 rtadvd FreeBSD 7 router config up for about 48 hours now
with XP SP3 and Vista SP1 and Mac OSX IPv6 connectivity working flawlessly,
including IPv6 routing through the FreeBSD 7 machine.

I am running SP1 on Vista (not sure your patchlevel, but I assume the same)

I am not experiencing the "Depreciated" state symptoms on Windows (or Mac)
you are seeing, and about the only thing different that I can think of is
that I specified the ipv6 addresses and prefix in my rtadvd.conf rather than
letting it attempt to learn that configuration automatically.

e.g.
fxp0:\
:addr="[IPv6 Prefix]"refixlen#64:

where "[IPv6 Prefix]" would be something like "2001:db8:1234::"

Sorry that I can not be of more help. Is your interface/address
"depreciated" state taking longer than 48 hours to occur, or is it happening
fairly quickly ? My default lifetimes are showing as ~7 days for Temporary,
and ~30 days for Public addresses. Given that information, I am guessing
that you only see this problem after at least a week goes by ?

I think I understand why ipconfig /renew6 is not fixing the issue, but not
why it is occuring in the first place. {It does not fix the issue since
/renew6 operates on DHCP6 level (which is not where the interface addresses
are being sent/defined) since you are using the "O" flag rather than the "M"
flag in your router advertisements.} Regardless, the DHCP server would have
to go down, or loss of connectivity would have to occur between the hosts...

Is it possible that rtadvd is seeing a different configuration (on the
FreeBSD or learned router interfaces) after a given period of time, and
changes the advertisements (causing depreciated state on the clients) Just a
thought. You might want to hard-wire your rtadvd.conf to a specific ipv6
prefix (like my example) to see if that helps.

Good Luck.

--_Dave

On 2008-05-25, GadgetDave <(E-Mail Removed)> wrote:
> I am not experiencing the "Depreciated" state symptoms on Windows (or Mac)
> you are seeing, and about the only thing different that I can think of is
> that I specified the ipv6 addresses and prefix in my rtadvd.conf rather than
> letting it attempt to learn that configuration automatically.
>
> e.g.
> fxp0:\
> :addr="[IPv6 Prefix]"refixlen#64:
>
> where "[IPv6 Prefix]" would be something like "2001:db8:1234::"

Currently, I'm trying this solution, and I have not seen deprecated
addresses yet. Hopefully this works around the problem.

> Sorry that I can not be of more help. Is your interface/address
> "depreciated" state taking longer than 48 hours to occur, or is it happening
> fairly quickly ? My default lifetimes are showing as ~7 days for Temporary,
> and ~30 days for Public addresses. Given that information, I am guessing
> that you only see this problem after at least a week goes by ?

The delay before deprecation was variable, sometimes a few hours and
sometimes several days.

> I think I understand why ipconfig /renew6 is not fixing the issue, but not
> why it is occuring in the first place. {It does not fix the issue since
> /renew6 operates on DHCP6 level (which is not where the interface addresses
> are being sent/defined) since you are using the "O" flag rather than the "M"
> flag in your router advertisements.} Regardless, the DHCP server would have
> to go down, or loss of connectivity would have to occur between the hosts...

No, /renew6 does cause stateless autoconfigured addresses (with rtadvd)
to be renowed, too. This appears clearly in the network capture:
Windows sends a new router sollicitation.

> Is it possible that rtadvd is seeing a different configuration (on the
> FreeBSD or learned router interfaces) after a given period of time, and
> changes the advertisements (causing depreciated state on the clients) Just a
> thought. You might want to hard-wire your rtadvd.conf to a specific ipv6
> prefix (like my example) to see if that helps.

It looks like it does help.

Currently, my interpretation is this:
* when IPv6 connectivity breaks (due to daily short disconnects from my
ISP, which may go unnoticed some days), rtadvd is killed
* when killed, rtadvd sends a last message to mark all addresses as
deprecated (I have not checked the source code yet, to see if this is
true)
* Windows marks the old addresses as deprecated
* when IPv6 connectivity goes up again, rtadvd is restarted
* when it receives the new router advertisement messages, Windows
resets the preferred lifetimes, but does not un-deprecate the
addresses. (If this is what happens, I believe this could be
considered a bug, or at least sub-optimal behavior).