Learn how to use the Teredo Tunneling Pseudo-Interface (Tunneling) to access private networks behind a firewall when you are connected through public Internet This article gives an introduction to the Teredo Tunneling Pseudo-Interface (Tunneling), and shows in detail how it can be used by end users in order to access private networks behind a firewall when the user is connected through public Internet. The article also describes in general terms how SSL or IPSec tunnels work and what they do. Finally, this article provides links where more information on using these protocols can be found. Teredo is a Network Address Translation (NAT) protocol that provides IPv6 connectivity when IPv6/IPv4 hosts are located behind one or multiple IPv4 routers, where the routers do not support IPv6. Teredo is specified in RFC4380. It belongs to the same family of tunneling protocols as 6to4 and ISATAP, which are covered in other articles on this site. All these protocols use single-address configuration, which means that all IPv6 hosts behind the same router can use the same Teredo/6to4/ISATAP address; however each host must be configured to use this address in order to receive traffic from other hosts that are located outside the private network. When using Teredo, only one IPv6 address (the "Teredo address") is needed to receive traffic from remote hosts; the Teredo address is the same for all hosts behind the same router. This is in contrast to 6to4 or ISATAP where each host must be configured with a unique IPv4 address (6to4 IPv6 addresses are used as well, but they are all derived from an IPv4 address). To allow a host to receive traffic from a remote host outside its private network, a hole must be opened in the router's firewall. At least one IPv6 address that can be reached to the outside world (not the Teredo address, but an external interface to it), must be created. The router itself must be dual-stacked to allow two Teredo interfaces (one each for the inside and outside) to work at the same time. The table below summarizes steps required for using Teredo:Teredo supports both automatic and manual configurations to provide hosts inside a private network with access to the Internet through a public network when there are no public IPv6 internet service providers available in that region. In the absence of a public provider, Teredo is an option for deployment. In cases where a NAT64 IPv6 transition technique is used for access to the global Internet, Teredo can be used as a fallback for hosts that cannot use NAT64. In the scenario described here, there are two separate Teredo servers. One server is located in a private network behind a NAT64 device and supports hosts that have been configured to use it as their Teredo server. The other server is located outside the private network and supports hosts that have been configured to use it for this purpose. 8eeb4e9f32 49
- wayminmatize