Method and system for switching between duplicated network interface adapters for host computer communications
First Claim
1. A method of switching from a first network adapter, having a first physical address, to a second network adapter, having a second physical address, to provide a first host, having a first logical address with duplicated functionality for TCP/IP communications with a plurality of hosts including a second host over a network, the method comprising the steps of:
- (a) disconnecting the first network adapter when a fault of the first network adapter has been detected by the first host;
(b) activating the second network adapter and initializing a network table stored therein;
(c) initiating a transmission of a control message from the first host to the second host;
(d) as a result of the control message initiated at step (c), broadcasting an ARP request message from the second network adapter to the hosts on the network, thereby causing the second host to update a network table thereof so that the first logical address is associated with the second physical address;
(f) transmitting the control message from the second network adapter to the second host by using address information contained in an ARP response message received from the second host;
(g) receiving a response message from the second host in reply to the control message; and
(h) recognizing the reception of the response message as completion of the response of switching from the first network adapter to the second network adapter.
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Accused Products
Abstract
A method and system for switching between duplicated network adapters in order to provide a host computer with fault-tolerant functionality for TCP/IP communication with a plurality of other hosts over a network. A first host is equipped with a first and second network adapters, which constructs a hot standby system. When a fault of the first network adapter has been detected, the first host disconnects the first network adapter and activates the second network adapter. The first host then initializes its own network table (or ARP cache) and initiates transmission of a control message addressed to the second host. This control message is an echo request message defined in the ICMP protocol. The second network adapter broadcasts an ARP request message to all hosts on the network. The second host replies to this ARP request message by returning an ARP response message. The second network adapter transmits the control message to the second host by using address information contained in the ARP response message. Upon receipt of a response message from the second host in reply to the control message, the first host recognizes it as the completion of the process of switching from the first network adapter to the second network adapter.
123 Citations
15 Claims
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1. A method of switching from a first network adapter, having a first physical address, to a second network adapter, having a second physical address, to provide a first host, having a first logical address with duplicated functionality for TCP/IP communications with a plurality of hosts including a second host over a network, the method comprising the steps of:
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(a) disconnecting the first network adapter when a fault of the first network adapter has been detected by the first host; (b) activating the second network adapter and initializing a network table stored therein; (c) initiating a transmission of a control message from the first host to the second host; (d) as a result of the control message initiated at step (c), broadcasting an ARP request message from the second network adapter to the hosts on the network, thereby causing the second host to update a network table thereof so that the first logical address is associated with the second physical address; (f) transmitting the control message from the second network adapter to the second host by using address information contained in an ARP response message received from the second host; (g) receiving a response message from the second host in reply to the control message; and (h) recognizing the reception of the response message as completion of the response of switching from the first network adapter to the second network adapter. - View Dependent Claims (2, 3, 4)
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5. A method of switching from a first network adapter, having a first physical address, to a second network adapter, having a second physical address, to provide a first host, having a first logical address, with duplicated functionality for TCP/IP communications with a plurality of other hosts including a second host over a network, the method comprising the steps of:
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(a) disconnecting the first network adapter when a fault of the first network adapter has been detected by the host; (b) activating the second network adapter; and (c) sending an ARP response message from the first host to the second host via the second network adapter, thereby causing the second host to update a network table thereof so that the first logical address is associated with the second physical address. - View Dependent Claims (6, 7)
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8. A system for switching from a first network adapter, having a first physical address, to a second network adapter, having a second physical address, to provide a first host, having a first logical address, with duplicated functionality for TCP/IP communications with a plurality of other hosts including a second host over a network, the system comprising:
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(a) fault detection means for detecting a fault of the first network adapter; (b) activation means for disconnecting the first network adapter in response to the fault detected by said fault detection means, and activating the second network adapter as an alternative to the first network adapter; (c) control message transmission means for initiating a transmission of a control message from the first host to the second host vial the second network adapter activated by said activation means, the control message causing an ARP request to be sent to the second host, thereby making the second host update a network table thereof so that the first logical address is associated with the second physical address; and (d) completion recognizing means for receiving a response message from the second host in reply to the control message sent from said control message transmission means, and recognizing the reception of the response message as completion of a process of switching from the first network adapter to the second network adapter. - View Dependent Claims (9, 10, 11, 15)
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12. A system for switching from a first network adapter, having a first physical address, to a second network adapter, having a second physical address, to provide a first host, having a first logical address, with duplicated functionality for TCP/IP communications with a plurality of other hosts including a second host over a network, the system comprising:
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(a) fault detection means for detecting a fault of the first network adapter; (b) activation means for disconnecting the first network adapter in response to the fault detected by said fault detection means, and activating the second network adapter as an alternative to the first network adapter; and (c) ARP message transmission means for sending an ARP response message from the first host to the second host via the second network adapter activated by said activation means, thereby making the second host update a network table thereof so that the first logical address be associated with the second physical address. - View Dependent Claims (13, 14)
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Specification