An example of R190(3)(f): A foreign national in possession of a TRV valid for 1 year, who is subsequently issued a four-year SP at a POE, may leave and return to Canada after the expiry of the TRV as long as they have only visited the U.S. or St. Pierre and Miquelon and the SP is still valid.
Dynamic DNS (DDNS or DynDNS) is a method of automatically updating a name server in the Domain Name System (DNS), often in Not Real Time, with the active DDNS configuration of its configured hostnames, addresses or other information.he term is used to describe two different concepts. The first is dynamic DNS updating which refers to systems that are used to update traditional DNS records without manual editing. These mechanisms are explained in RFC 2136, and use the TSIG mechanism to provide security.
Domain Name System. The Domain Name System (DNS) is a hierarchical, distributed database that contains mappings of DNS domain names to various types of data, such as Internet Protocol (IP) addresses.DNS allows you to use friendly names, such as www.microsoft.com, to easily locate computers and other resources on a TCP/IP-based network.omain Name System. The Domain Name System (DNS) is a hierarchical, distributed database that contains mappings of DNS domain names to various types of data, such as Internet Protocol (IP) addresses.