Patent ID: 11876709
Assignee: NIPPON TELEGRAPH AND TELEPHONE CORPORATION
Field: Digital communication (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A monitoring apparatus for monitoring a plurality of network devices disposed in a network in a virtual infrastructure, the virtual infrastructure using a virtual router,
wherein the monitoring apparatus stores address management information that indicates address information of each of the network devices and also indicates a connection to each of the network devices, and
wherein the network devices comprise:
a first router in which the virtual router is formed, wherein the first router functions as a master during a non-failure time;
a second router in which the virtual router is formed, wherein the second router functions as the master at a time of a failure and is different from the first router; and
one or more switches;

the monitoring apparatus, including one or more processors, comprising:
a detection section configured to detect a failure of the first router based on notifications received from one or more of the network devices;
an acquisition section configured to acquire information from each of the network devices and update the address management information using the acquired information, the acquired information comprising: (i) a first Address Resolution Protocol (ARP) table acquired from the first router, (ii) a second ARP table acquired from the second router, and (iii) a respective Media Access Control (MAC) table from each of the switches; and
a rewriting section configured to rewrite the address management information such that the second router has virtual address information set in the virtual router based on the acquired information, the rewriting comprising: (i) removing one or more entries from the first ARP table, (ii) adding one or more entries to the second ARP table, and (iii) removing one or more entries from each of the MAC tables.