Method and system for initializing host location information across smart bridge topology changes
First Claim
1. In a bridged network having a plurality of hosts coupled to a plurality of segments interconnected by at least one bridge, a method for initializing host location information in response to a network topology change, comprising:
- obtaining prior host location information, said prior host location information being at least a partial representation of host locations in the bridged network before the network topology change;
obtaining hints about changes in host locations as a result of the network topology change;
modifying the prior host location information according to said hints to obtain initial host location information, said initial host location information being at least an approximate account of the host locations after the network topology change.
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Accused Products
Abstract
A network includes multiple segments and bridges interconnecting the segments, with hosts coupled to the segments. The bridges are smart bridges that each perform a host location initialization function. The host location initialization function in one bridge is performed in corporation with all other bridges in the bridged network via an instance through a propagation order spanning tree (POST). The initialization method includes obtaining prior host location information which is at least a partial representation of the host locations in the bridged network before the network topology change, obtaining hints on host location changes resulting from the network topology change, and modifying the prior host location information according to the hints to construct host location information for initialization. Location information for at least a portion of the hosts in the bridged network is preserved or discovered quickly each time when the network topology changes.
53 Citations
36 Claims
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1. In a bridged network having a plurality of hosts coupled to a plurality of segments interconnected by at least one bridge, a method for initializing host location information in response to a network topology change, comprising:
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obtaining prior host location information, said prior host location information being at least a partial representation of host locations in the bridged network before the network topology change;
obtaining hints about changes in host locations as a result of the network topology change;
modifying the prior host location information according to said hints to obtain initial host location information, said initial host location information being at least an approximate account of the host locations after the network topology change. - View Dependent Claims (2, 3, 5, 9, 11, 13)
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4. The method of claim 0, wherein the bridged network includes at least one other bridge in addition to the root bridge, and wherein obtaining the prior host location information further comprises:
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sending from the root bridge to the at least one other bridge a request for additional host location information; and
receiving from the at least one other bridge the additional host location information.
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- 6. The method of claim 0, wherein the additional host location information is determined by the at least one other bridge based on the list of host identifiers received from the root bridge and host location information stored in the at least one other bridge.
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7. The method of claim 0, wherein the request for additional host location information is sent via a spanning tree having the root bridge as the root of the spanning tree, and wherein sending from the root bridge to the at least one other bridge a request for additional host location information further comprises:
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sending from the root bridge to a first bridge a request for additional host location information not stored in the root bridge;
extracting from host location information stored in the first bridge an additional list of segment identifiers not included in the request;
adding the additional segment identifiers to the request; and
sending the request from the first bridge to a second bridge.
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- 10. The method of claim 0, wherein modifying the prior host location information includes changing the identified segment identifiers in the prior host location information to a predetermined default name.
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14. In a bridged network having a plurality of hosts each coupled to one of a plurality of network segments interconnected by a plurality of bridges, each host having a location in the bridged network, each bridge storing a piece of host location information, a method for initializing host location information stored in each bridge, comprising:
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detecting changes in network topology;
in response to a detected change in network topology, sending a request for host locations initialization from one bridge to other bridges in the bridged network;
receiving responses from said other bridges;
constructing initial host location information based on said responses and on host location information stored in said one bridge, said initial host location information being at least an approximate account of the locations of at least a portion of said hosts in the bridged network after the change in network topology; and
sending said initial host location information to said other bridges.
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15. The method of claim 0, wherein sending a request for host locations initialization further comprises:
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sending said request to a first group of neighbor bridges, said first group of neighbor bridges being coupled to a same network segment as said one bridge; and
in response to one of said first group of neighbor bridges having received said request, sending a sub-request for host locations initialization from said one of said first group of neighbor bridge to a second group of neighbor bridges, said second group of neighbor bridges being coupled to a same network segment as said one of said first group of neighbor bridges.
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16. The method of claim 0, wherein receiving responses from said other bridges further comprises:
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receiving in one of said first group of neighbor bridges sub-responses from said second group of neighbor bridges; and
receiving a response from said one of said first group of neighbor bridges, said response comprising a combination of said sub-responses.
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17. The method of claim 0, wherein said piece of host location information stored in each bridge comprises a list of host identifiers each identifying a host and each mapped to a segment identifier identifying a network segment to which said identified host is coupled, and wherein said request includes a list of segment identifiers extracted from the piece of host location information stored in said one bridge sending said request.
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18. The method of claim 0, wherein said sub-request includes a list of segment identifiers extracted from said one of said first group of neighbor bridges sending said sub-request.
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19. The method of claim 0, wherein said sub-responses comprise host location information extracted from said second group of neighbor bridges, and wherein said responses comprise host location information extracted from said first group of neighbor bridges and from said second group of neighbor bridges.
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20. The method of claim 0, wherein said sub-responses comprise segment-renaming hints associated with network segments coupled to said second group of neighbor bridges, and wherein said responses comprise segment-renaming hints associated with said first group of neighbor bridge and with said second group of neighbor bridges.
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21. The method of claim 0, wherein each bridge stores a total network report, said total network report being a description of bridge-to-network connections in the bridged network, wherein said responses comprise information of bridge-to-network connections associated with said other bridges, and wherein constructing initial host location information comprises:
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constructing a new total network report based on said responses;
inferring segment-renaming hints by comparing said new total network report with said total network report stored in said one bridge that has received said responses; and
constructing said initial host location information based on said inferred hints, said responses, and host location information stored in said one bridge.
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22. A bridged network, comprising:
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a plurality of network segments;
a plurality of hosts, each coupled to a network segment; and
a plurality of smart bridges, each having memory spaces for storing a host locations table, and configured to initiate a host locations initialization instance upon detecting a change in network topology, said host location initialization instance comprising;
sending a request for host locations initialization from one bridge to other bridges in the bridged network;
receiving responses from said other bridges;
constructing initial host location information based on said responses and on said host locations table in said one bridge, said initial host location information being at least an approximate account of the locations of at least a portion of said hosts in the bridged network after the change in network topology;
sending said initial host location information to said other bridges; and
rewriting said host location table in each bridge in accordance with said initial host location information.
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23. The bridged network of claim 0, wherein sending a request for host locations initialization further comprises sending said request to a first group of neighbor bridges, each one of said first group of neighbor bridges being coupled to a same network segment as said one bridge, and being configured to, in response to receiving said request, send a sub-request for host locations initialization to a second group of neighbor bridges, said second group of neighbor bridges being coupled to a same network segment as said one of said first group of neighbor bridges.
- 24. The bridged network of claim 0, wherein receiving responses from said other bridges further comprises receiving in one of said first group of neighbor bridges sub-responses from said second group of neighbor bridges, and wherein the one of said first group of neighbor bridges being configured to send a response to said one bridge sending the request, said response comprising a combination of said sub-responses.
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25. The bridged network of claim 0, wherein said host locations table stored in each bridge comprises a list of host identifiers each identifying a host and each mapped to a segment identifier identifying a network segment to which said identified host is coupled, and wherein said request includes a list of segment identifiers extracted from the piece of host location information stored in said one bridge sending said request.
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27. The bridged network of claim 0, wherein said sub-responses comprising host location information extracted from said second group of neighbor bridges, and wherein said responses comprising host location information extracted from said first group of neighbor bridges and from said second group of neighbor bridges.
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28. The bridged network of claim 0, wherein said sub-responses comprising segment-renaming hints associated with network segments coupled to said second group of neighbor bridges, and wherein said responses comprising segment-renaming hints associated with said first group of neighbor bridge and with said second group of neighbor bridges.
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29. The bridged network of claim 0, wherein each bridge includes memory spaces for storing a total network report, said total network report being a description of bridge-to-network connections in the bridged network, wherein said responses comprise information of bridge-to-network connections associated with said other bridges, and wherein said one bridge receiving said responses is configured to:
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construct a new total network report based on said responses;
infer segment-renaming hints by comparing said new total network report with said total network report stored in said one bridge; and
construct said initial host location information based on said inferred hints, said responses, and host location information stored in said one bridge.
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30. A smart bridge in a bridged network having network segments and hosts coupled to said network segments, comprising:
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a plurality of bridge ports, at least a portion of the bridge ports being connected to at least a portion of said network segments, each bridge port providing transmit and receive services for the smart bridge;
at least one segment inventory module coupled to said bridge ports and configured to detect network topology changes associated with said portion of said network segments;
a host locations initialization module coupled to said segment inventory modules and configured to initiate a host locations initialization instance in response to detected change in network topology;
a memory unit storing a host location table, said host location table being a description of locations of said hosts in said bridged network; and
wherein said host locations initialization instance comprising;
transmitting a request to join said instance to said bridged network via said bridge ports;
receiving responses from said bridged network via said bridge ports;
constructing initial host location information based on said responses and on said host locations table, said initial host location information being at least an approximate account of the locations of at least a portion of said hosts in the bridged network after the change in network topology;
sending said initial host location information to said bridged network via said ports; and
rewriting said host location table in said smart bridge in accordance with said initial host location information.
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- 31. The smart bridge of claim 0, further comprising a location revision module configured to update said host location table based on data packets received by said smart bridge from said hosts in the bridged network.
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32. The smart bridge of claim 0, further comprising a topology acquisition module configures to provide a total network report after said change in network topology, said total network report being a description of bridge-to-network connections in said bridged network.
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35. The smart bridge of claim 0, wherein said host locations initialization module is further configured to, in response to receiving a first request to join a host locations initialization instance, transmit a second request to join said instance to the bridged network via said bridge ports.
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36. The smart bridge of claim 0, wherein said host location table comprises a list of host identifiers each identifying a host and each is mapped to a segment identifier identifying a segment to which the identified host is coupled, and wherein said request to join said instance includes a list of segment identifiers extracted from said host location table.
Specification