Standby router protocol
DCFirst Claim
1. A router for use with a network segment having a plurality of routers and a plurality of hosts which address data packets to an active router from the plurality of routers, the router having a memory and a processor and comprising:
- a primary router address stored in the router;
a group virtual address stored in the router, which group virtual address is adopted by the router when it becomes the active router of the network segment;
means for adopting the group virtual address;
means for issuing a coup message to notify a current active router that the router will attempt to become the active router; and
means for disabling, at least temporarily, the means for issuing a coup message.
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Accused Products
Abstract
A system and protocol are provided for routing data packets from a host on a LAN through a virtual address belonging to a group of routers. The host is configured to point to the virtual address so that the packets it sends out of its LAN are always directed to a virtual router which may be any one of the group of routers. An active router in the group of routers emulates the virtual router. A standby router, also from the group of routers, backs up the active router so that if the active router becomes inoperative, the standby router automatically begins emulating the virtual router. The host router does not know which router from the group is actually handling the data packets it sends. If the standby router becomes inoperative or takes over for the active router, other routers in the group hold an election to determine which of them should take over for the standby router.
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Citations
31 Claims
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1. A router for use with a network segment having a plurality of routers and a plurality of hosts which address data packets to an active router from the plurality of routers, the router having a memory and a processor and comprising:
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a primary router address stored in the router; a group virtual address stored in the router, which group virtual address is adopted by the router when it becomes the active router of the network segment; means for adopting the group virtual address; means for issuing a coup message to notify a current active router that the router will attempt to become the active router; and means for disabling, at least temporarily, the means for issuing a coup message. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A network segment providing a redundant routing capability, the network segment comprising:
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at least one host on a LAN, said host including means for addressing data packets to a virtual router; at least two physical routers connecting the host'"'"'s LAN to at least one other network segment, each router capable of assuming the states of active and standby router, the active router communicating with the host and the standby router backing up the active router; and means for selecting the active router and the standby router from among the at least two routers, wherein said active router includes means for emulating a virtual router, and wherein each physical router is provided with the ability to issue coup messages for notifying the active router that the physical router will attempt to become the active router, and wherein the ability to issue coup messages can be disabled at least temporarily. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
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21. A method of backing up a router with which a host communicates in a network having multiple routers, each router having a priority, the method comprising the following steps:
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specifying an active router for routing data packets from the host; specifying a standby router which backs up the active router; causing said active router to emulate a virtual router; causing the host to address data packets to said virtual router; and automatically selecting a new active router based upon a comparison of the priorities of the multiple routers in the network, wherein said active and standby routers are provided with the ability to issue coup messages for notifying another active router that the active or standby router will attempt to become the active router, and wherein the ability to issue coup messages can be disabled at least temporarily. - View Dependent Claims (22, 23, 24, 25, 26, 27, 28)
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29. A router for use with a network segment having a plurality of routers and a plurality of hosts which address data packets to an active router from the plurality of routers, the router comprising:
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a memory; a processor coupled to said memory; one or more interfaces for sending and receiving data packets on a network, wherein said memory and said processor are adapted to provide (a) a primary router address and (b) a group virtual address which is adopted by the router when it becomes the active router of the network segment, and wherein said memory and said processor are adapted to (c) issue a coup message, through said one or more interfaces, to notify a current active router when the router will attempt to become the active router, and (d) disable, at least temporarily, the router'"'"'s ability to issue a coup message. - View Dependent Claims (30, 31)
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Specification