Since a couple of weeks (might be a windows 10 update), my Windows 10 computers (not any iOS oder Android Devices) get assigned a stateful+stateless ipv6 address, although no M Flag aka statless addresses are configured by the router. This is definitively new. Did anyone else experience this?
/etc/config/dhcp
config dhcp 'lan'
option interface 'lan'
option start '100'
option limit '150'
option leasetime '12h'
option dhcpv6 'server'
option ra 'server'
option ra_management '0'
Here is a wireshark log:
Primary Router Advertisment
Ethernet II, Src: SERVER (SERVER), Dst: CLIENT (f8:16:54:d8:85:97)
Internet Protocol Version 6, Src: fe80::da58:d7ff:fe00:4cc2, Dst: fe80::b5a5:6c9:cae7:9c67
Internet Control Message Protocol v6
Type: Router Advertisement (134)
Code: 0
Checksum: 0xae99 [correct]
[Checksum Status: Good]
Cur hop limit: 64
Flags: 0x40, Other configuration, Prf (Default Router Preference): Medium
**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): 1800
Reachable time (ms): 0
Retrans timer (ms): 0
ICMPv6 Option (Source link-layer address : d8:58:d7:00:4c:c2)
Type: Source link-layer address (1)
Length: 1 (8 bytes)
Link-layer address: CzNicZSP_00:4c:c2 (d8:58:d7:00:4c:c2)
ICMPv6 Option (MTU : 1492)
Type: MTU (5)
Length: 1 (8 bytes)
Reserved
MTU: 1492
ICMPv6 Option (Prefix information : 2001:XXXXXX::/64)
Type: Prefix information (3)
Length: 4 (32 bytes)
Prefix Length: 64
Flag: 0xc0, On-link flag(L), Autonomous address-configuration flag(A)
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: 7200
Preferred Lifetime: 1800
Reserved
Prefix: 2001:XXXXXX::
ICMPv6 Option (Route Information : Medium 2001:XXXX::/48)
Type: Route Information (24)
Length: 3 (24 bytes)
Prefix Length: 48
Flag: 0x00, Route Preference: Medium
...0 0... = Route Preference: Medium (0)
000. .000 = Reserved: 0
Route Lifetime: 7200
Prefix: 2001:XXXX
ICMPv6 Option (Recursive DNS Server 2001:XXXXX::1)
Type: Recursive DNS Server (25)
Length: 3 (24 bytes)
Reserved
Lifetime: 1200
Recursive DNS Servers: 2001:XXXXX:1
ICMPv6 Option (DNS Search List Option fmf.netz)
Type: DNS Search List Option (31)
Length: 4 (32 bytes)
Reserved
Lifetime: 1200
Domain Names: fmf.netz
Padding
ICMPv6 Option (Advertisement Interval : 600000)
Type: Advertisement Interval (7)
Length: 1 (8 bytes)
Reserved
Advertisement Interval: 600000
Then the client sends a Identity Association for Non-temporary Address ::86b with the address that gets registered as DHCPv6 Addresses in LUCI
Frame 5980: 162 bytes on wire (1296 bits), 162 bytes captured (1296 bits) on interface 0
Ethernet II, Src: IntelCor_d8:85:97 (f8:16:54:d8:85:97), Dst: IPv6mcast_01:00:02 (33:33:00:01:00:02)
Internet Protocol Version 6, Src: fe80::b5a5:6c9:cae7:9c67, Dst: ff02::1:2
User Datagram Protocol, Src Port: 546, Dst Port: 547
DHCPv6
Message type: Confirm (4)
Transaction ID: 0xc2e275
Elapsed time
Option: Elapsed time (8)
Length: 2
Value: 0000
Elapsed time: 0ms
Client Identifier
Option: Client Identifier (1)
Length: 14
Value: 000100012458f34ff0def1678103
DUID: 000100012458f34ff0def1678103
DUID Type: link-layer address plus time (1)
Hardware type: Ethernet (1)
DUID Time: Apr 29, 2019 01:27:11.000000000 Mitteleuropäische Sommerzeit
Link-layer address: f0:de:f1:67:81:03
**Identity Association for Non-temporary Address**
** Option: Identity Association for Non-temporary Address (3)**
Length: 40
Value: 25f81654000000000000000000050018200116200e620001…
IAID: 25f81654
T1: 0
T2: 0
IA Address
Option: IA Address (5)
Length: 24
Value: 2001XXXXXX000086b0000000000000000
**IPv6 address: 2001:XXXXX::86b**
Preferred lifetime: 0
Valid lifetime: 0
Vendor Class
Option: Vendor Class (16)
Length: 14
Value: 0000013700084d53465420352e30
Enterprise ID: Microsoft (311)
vendor-class-data: MSFT 5.0
Option Request
Option: Option Request (6)
Length: 6
Value: 001100170018
Requested Option code: Vendor-specific Information (17)
Requested Option code: DNS recursive name server (23)
Requested Option code: Domain Search List (24)
Server then replies by this:
Frame 5981: 168 bytes on wire (1344 bits), 168 bytes captured (1344 bits) on interface 0
Ethernet II, Src: CzNicZSP_00:4c:c2 (d8:58:d7:00:4c:c2), Dst: IntelCor_d8:85:97 (f8:16:54:d8:85:97)
Internet Protocol Version 6, Src: fe80::da58:d7ff:fe00:4cc2, Dst: fe80::b5a5:6c9:cae7:9c67
User Datagram Protocol, Src Port: 547, Dst Port: 546
DHCPv6
Message type: Reply (7)
Transaction ID: 0xc2e275
Server Identifier
Option: Server Identifier (2)
Length: 10
Value: 00030001d858d7004cc2
DUID: 00030001d858d7004cc2
DUID Type: link-layer address (3)
Hardware type: Ethernet (1)
Link-layer address: d8:58:d7:00:4c:c2
Client Identifier
Option: Client Identifier (1)
Length: 14
Value: 000100012458f34ff0def1678103
DUID: 000100012458f34ff0def1678103
DUID Type: link-layer address plus time (1)
Hardware type: Ethernet (1)
DUID Time: Apr 29, 2019 01:27:11.000000000 Mitteleuropäische Sommerzeit
Link-layer address: f0:de:f1:67:81:03
SOL_MAX_RT
Option: SOL_MAX_RT (82)
Length: 4
Value: 0000003c
DNS recursive name server
Option: DNS recursive name server (23)
Length: 16
Value: 20011xxxxx0000001
1 DNS server address: 2001:xxxxxxx:1
Domain Search List
Option: Domain Search List (24)
Length: 10
Value: 03666d66046e65747a00
DNS Domain Search List
Domain Search List FQDN: fmf.netz
Identity Association for Non-temporary Address
Option: Identity Association for Non-temporary Address (3)
Length: 18
Value: 25f816540000000000000000000d00020004
IAID: 25f81654
T1: 0
T2: 0
Status code
Option: Status code (13)
Length: 2
Value: 0004
Status Code: NotOnLink (4)
Status code
Option: Status code (13)
Length: 2
Value: 0004
Status Code: NotOnLink (4)