Hitachi, Ltd.

Hitachi Communication Technologies, Ltd.

Shinsuke Shimizu

Hiroaki Miyata

Daiki Nozue

Norihiro Kambe

Migaku Ota

Yoshitaka Sakamoto

Hisao Taguchi

A method for processing data received from at least one of VLANs, the method including: obtaining, based on a VLAN tag included in a MAC header of a MAC frame received from the VLAN and a first destination IP address included in an IP header of the MAC frame, a second destination IP address, changing the first destination IP address of the IP header to the second destination IP address, and generating an IP packet by deleting the MAC header from the MAC frame.

VLAN server

The access server receives an authentication packet including an authentication result, a port change setting information, a port change time, a filtering setting information and a filtering time from the authentication server. The access server stores the respective information in the authentication packet into a memory. The access server refers to the memory, and in the case where the port change setting information on an arbitrary user identifier is set to perform port change, when it becomes the port change time, the access server changes the output destination of a packet from a user terminal to, for example, a proxy server B from a proxy server A. Besides, in the case where the filtering setting information on an arbitrary user identifier is set to perform filtering, when it becomes the filtering start time, the access server performs filtering on the port to which the user terminal is connected.

Access server and connection restriction method

A packet routing arrangement, when receiving a request to join or leave a multicast group from a host unregistered to that group, a response is sent exclusively to the unregistered host. In the packet routing arrangement, when receiving a request packet from a host to join or leave a group, including the identifier of the group, it is determined whether the source host of the packet is registered to that group; and, if it is not registered, the first group identifier is changed to a second group identifier assigned to another delivery server delivering information to the other unregistered host and the packet is transferred to this other delivery server. When receiving a packet containing certain information from this delivery server, the second group identifier included in the received packet is changed to the first group identifier and the packet is transmitted to the unregistered host.

Multicast packet routing arrangements for group-membership handling

One physical VLAN server provides a plurality of VLANs with services. VLANs #to #are connected to the VLAN server though a switching hub. The VLAN server includes server processes #to #corresponding to the VLANs #to #, respectively, for providing the VLANs with services. The server processes #to #each have internal IP addresses N, N, and N. The VLAN server has external IP addresses G, G, and Gfor the VLANs #to #, respectively. When a client #-on the VLAN #issues data to the VLAN server with the destination IP address being set to G, a receiving-VLAN-tag-NAT processing section of a device driver in the VLAN server changes the destination IP address from Gto Nwith the use of a VLAN tag V, and the server process #receives the data

Growing community of inventors

Yokohama, Japan

Shinsuke Shimizu