Enables or disables Network Address Translation (NAT) traversal on a TcpListener instance.
Assembly: System (in System.dll)
The method is used to enable or disable NAT traversal for a TcpListener instance. NAT traversal may be provided using Teredo, 6to4, or an ISATAP tunnel.
When the allowed parameter is true, the IPProtectionLevel option on the associated socket is set to Unrestricted. This may allow NAT traversal for a TcpListener depending on firewall rules in place on the system.
The method must be invoked prior to calling the Start method to begin listening for incoming connection requests (before the socket is bound). If method is called after the Start method, then an InvalidOperationException will be thrown.
A Teredo address is an IPv6 address with the prefix of 2001::/32. Teredo addresses can be returned through normal DNS name resolution or enumerated as an IPv6 address assigned to a local interface.