why teredo IP Address keep changing?

mahmoud nezar sarhan asked:

I managed to configure teredo on windows 7 but I come up with one problem … teredo IP address keep changing .
I noticed that terendo stat keep change too , it moving from dormant to enabled and vica versa

when I run (ipconfig /all) it give me :

Windows IP Configuration

   Host Name . . . . . . . . . . . . : mahmoud-PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Realtek RTL8723AE Wireless LAN 802.11n PC
I-E NIC
   Physical Address. . . . . . . . . : 20-16-D8-E0-25-2A
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::bc13:29c3:a8c3:c74a%14(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.8.102(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : 30 أيار, 2016 07:16:29 م
   Lease Expires . . . . . . . . . . : 31 أيار, 2016 07:16:29 م
   Default Gateway . . . . . . . . . : 192.168.8.1
   DHCP Server . . . . . . . . . . . : 192.168.8.1
   DHCPv6 IAID . . . . . . . . . . . : 371201752
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1D-CA-DC-A6-58-2C-80-13-92-63

   DNS Servers . . . . . . . . . . . : 192.168.8.1
                                       192.168.8.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{5B08C959-60F6-48C1-BD72-E0E7F1323658}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e74:1c26:1903:3f57:f799(Pref
erred)
   Link-local IPv6 Address . . . . . : fe80::1c26:1903:3f57:f799%15(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

and if I running it again after a while it give me :

Windows IP Configuration

   Host Name . . . . . . . . . . . . : mahmoud-PC
   Primary Dns Suffix  . . . . . . . :
   Node Type . . . . . . . . . . . . : Hybrid
   IP Routing Enabled. . . . . . . . : No
   WINS Proxy Enabled. . . . . . . . : No

Wireless LAN adapter Wireless Network Connection:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Realtek RTL8723AE Wireless LAN 802.11n PC
I-E NIC
   Physical Address. . . . . . . . . : 20-16-D8-E0-25-2A
   DHCP Enabled. . . . . . . . . . . : Yes
   Autoconfiguration Enabled . . . . : Yes
   Link-local IPv6 Address . . . . . : fe80::bc13:29c3:a8c3:c74a%14(Preferred)
   IPv4 Address. . . . . . . . . . . : 192.168.8.102(Preferred)
   Subnet Mask . . . . . . . . . . . : 255.255.255.0
   Lease Obtained. . . . . . . . . . : 30 أيار, 2016 07:16:29 م
   Lease Expires . . . . . . . . . . : 31 أيار, 2016 07:16:29 م
   Default Gateway . . . . . . . . . : 192.168.8.1
   DHCP Server . . . . . . . . . . . : 192.168.8.1
   DHCPv6 IAID . . . . . . . . . . . : 371201752
   DHCPv6 Client DUID. . . . . . . . : 00-01-00-01-1D-CA-DC-A6-58-2C-80-13-92-63

   DNS Servers . . . . . . . . . . . : 192.168.8.1
                                       192.168.8.1
   NetBIOS over Tcpip. . . . . . . . : Enabled

Tunnel adapter isatap.{5B08C959-60F6-48C1-BD72-E0E7F1323658}:

   Media State . . . . . . . . . . . : Media disconnected
   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Microsoft ISATAP Adapter
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes

Tunnel adapter Teredo Tunneling Pseudo-Interface:

   Connection-specific DNS Suffix  . :
   Description . . . . . . . . . . . : Teredo Tunneling Pseudo-Interface
   Physical Address. . . . . . . . . : 00-00-00-00-00-00-00-E0
   DHCP Enabled. . . . . . . . . . . : No
   Autoconfiguration Enabled . . . . : Yes
   IPv6 Address. . . . . . . . . . . : 2001:0:4137:9e74:10f6:14d3:3f57:f799(Pref
erred)
   Link-local IPv6 Address . . . . . : fe80::10f6:14d3:3f57:f799%15(Preferred)
   Default Gateway . . . . . . . . . : ::
   NetBIOS over Tcpip. . . . . . . . : Disabled

note that ip version 6 of the teredo interface changed .
why this happening ? and how to solve this ? ( I’m behind a NAT if this make any difference )

thanks

My answer:


Teredo is a protocol that tunnels IPv6 traffic via UDP on IPv4 to a Teredo server, which then routes the IPv6 traffic onward to the Internet, or back toward you.

The Teredo IPv6 address you receive encodes the IPv4 address of the Teredo server and UDP port for your particular tunnel connection. If the tunnel disconnects and reconnects, these may change.

For instance, in the first case, your Teredo address encodes a Teredo server IPv4 address of 65.55.158.116 and UDP port 59132. In the second case, the IPv4 address is the same but the UDP port is 60204. So, we can tell that your tunnel disconnected and reconnected at least once.

Teredo also encodes the IPv4 RFC1918 address of the local machine, which in your case is 192.168.8.102.

All of these are necessary in order for the Teredo protocol to route packets correctly through your NAT.

In addition, the random address flags are set on each address, causing the IP address to have any of 4,096 possible values per Teredo server/UDP port combination. This provides a measure of resistance against IPv6 address scanning, which otherwise would be trivial for Teredo connections.

Teredo is fully explained in RFC 5991, the random flags in section 3.1, and security considerations in section 4.


View the full question and answer on Server Fault.

Creative Commons License
This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Unported License.