… the other day I had to decide "The case of the strange disappearance of Internet access in the local network".
2 pc with windows 7 on "board" connected to a home LAN.
An ADSL router with which the Internet is connected is connected to one PC. This is an internet connection. "shared" for the second pc.
Until recently, the local network worked smoothly, there were no problems with Internet access (both PCs worked around the clock for several months).
The access to the Internet on the second PC suddenly disappeared (the local network continued to operate smoothly).
An incident investigation revealed that there was a network intrusion from one of the torrent resources, resulting in "distributing" Internet on the local network, the Teredo network protocol was enabled:
In addition, the contents of the file were changed on the same PC.
It should be noted that in the event of a network attack of a virus infection of computers on the local network was not (on both PCs, the regularly updated Microsoft Security Essentials antivirus was installed and Windows Firewall was enabled).
Eliminating the cause of the failure was straightforward:
– delete the file
"The case of the strange disappearance of Internet access in the local network" closed…
– click Start;
– in the text field Find programs and files, type cmd;
– a line will appear under the Program heading.
– click it with the right mouse button;
– from the context menu, select Run as administrator;
– enter the password if the corresponding request appears;
– if the User Account Control window appears with the message “Allow the following program to make changes on this computer?”, Click Yes;
– in the opened Command Interpreter window after the system prompt (C: \ windows \ system32>) enter
netsh interface teredo set state disabled
– press Enter, the message OK will appear;
– after the system prompt (C: \ windows \ system32>) type exit, press Enter (or just close the Command Interpreter window).
1. Teredo is a network protocol designed to transmit IPv6 packets over IPv4 networks.
2. In Windows 7 for the protocol "answers" Microsoft Teredo Tunnel Adapter (Teredo Tunneling Pseudo-Interface; Driver File – \ Windows \ System32 \ drivers \
3. The most common Teredo protocol commands:
netsh interface teredo show state – Teredo status display;
netsh interface teredo set state client – enabling the Teredo client;
netsh interface teredo set state enterpriseclient — skip detection of the managed network;
netsh interface teredo set state server — turns on the Teredo server;
netsh interface teredo set state default – enable default state (client).
4. netsh (
5. Microsoft Teredo server is located at
6. Application of the Teredo protocol opens "hole", allowing unauthorized access to the local network.
7. teredo translated from English means "shipworm". A very symbolic name for the network protocol.