| 摘要 |
<p>A communication control device which is, for example, an IP line unit (73) provided in a monitoring apparatus of a monitoring system, and which communicates with a monitoring center via a VPN. The IP line unit (73) comprises a packet processing unit (101) which converts input packets into packets to be transmitted, a storage unit (103) which stores the virtual IP address of the IP line unit (73) in the VPN, and a judgment unit (105) which compares the source address in the transmission packets with the virtual IP address stored in the storage unit (103). The judgment unit (105) judges whether both the network portion and host portion of the source address respectively match the network portion and host portion of the virtual IP address. When the judgment result indicates a match, an encapsulation unit (107) encapsulates the packets. As a result, in a configuration in which the communication control device of a VPN is connected to a local network, communication failure due to the overlap of the local IP address with the virtual IP address is prevented.</p> |
