Patent ID: 8040881

Claim:
A printer comprising: a registration unit configured to register destination data indicating a client terminal that is notified of an event that occurred at the printer; a performing unit configured to perform processing for establishing a connection with the client terminal indicated by the registered destination data in response to the event occurring at the printer; a name resolution determination unit configured to determine whether a name resolution is possible; a destination determination unit configured to determine whether or not new destination data that is requested to be registered by the registration unit is described as an IP address; and a registration restriction unit configured to, in response to a request for registering the new destination data, restrict registration of the new destination data based on a determination by the destination determination unit that the new destination data is not described as the IP address and a determination by the name resolution determination unit that the name resolution is not possible, wherein the name resolution is a name resolution by a DNS (Domain Name System) server separate from the printer, wherein the destination determination unit is configured to determine that the new destination data is not described as the IP address, when the new destination data is described as non-IP-address data, wherein, when the destination determination unit determines that the new destination data is described as the non-IP-address data, and when the name resolution determination unit determines that the name resolution is possible, the registration unit is configured to register the non-IP-address data, and wherein, when the registration unit registers the non-IP-address data when the name resolution determination unit determines that the name resolution is possible, and when the name resolution determination unit subsequently determines that the name resolution is no longer possible, the registration restriction unit is configured to invalidate the registered non-IP-address data, and the registration unit is configured to re-register destination data indicating the client terminal upon a request from the client terminal, the re-registered destination data being an IP address corresponding to the invalidated non-IP-address data.