Cisco Technology, Inc.

John Lautmann

Frank Gerard Bordonaro

Kui Zhang

Satyanarayana Rao Raparla

Mark Denny

Andrew Joseph Mead

Ramanathan Kavasseri

Shankar Natarajan

Uwe Sellentin

Praveen Joshi

Scott Allan Bales

Arunkumar Bhushappagala Thippeswamy

Richard W Pratt

Scott Allen Bales

Sankha Basu

A method for operating a computer network has a source router transmit a first message to be received by an intermediate router of the computer network, the first message to activate the intermediate router to listen for a designated time period for the intermediate router to receive a second message. Upon receiving a second message by the intermediate router during the designated time period, the intermediate router responds to the second message in response to receiving the second message during the designated time period.

Method and apparatus for measuring latency of a computer network

Methods and devices are disclosed for changing the configuration state of a network device such as a router, a switch or a similar device without the need for a person to interpret a textual diff. According to some aspects of the invention, a programmatic diff file that includes the output of two comparisons is used as an input file to a program that 'rolls back' the current configuration state to a prior configuration state. According to other aspects of the invention, the output of a single comparison is input to an 'incremental diff' process, which adds new commands to a configuration state. According to preferred aspects of the invention, the output files generated by the comparison processes preserve the hierarchical context of each command in a programmatic format that is usable as direct input by the network device or by another device (such as a host controlled by a network administrator) that performs the incremental diff.

Using context-sensitive intelligent diffs to modify router configurations

A control mechanism enables a destination router to authenticate a response time request issued by a source router. The control mechanism uses a control message that is transmitted by the source router to the destination router. Receipt of the control message by the destination router causes the destination router to listen for a server request message for a designated response time. The source router, after sending the control message, transmits a server request message to the destination router. In the event that the destination router receives the server request message within the designated response time, then the destination router responds to the server request message by providing the request to service software. The control message may encapsulate a message that holds the response time request. The request message may be encrypted.

A new directory service is established for a peer router receiving a data packet from an end station on a local area network connected to a port of the peer router, the peer router hereinafter being referred to as the source router. The data packet is addressed to a destination address. The source router determines that the data packet is to be encapsulated as an encapsulated packet, and the encapsulated packet routed by a peer-to-peer protocol to a destination router. The destination router then transmits the packet onto a local area network to the destination address. The source router locates the proper peer destination router by use of a database. The database is maintained on a server, where the database has entries for destination address, and an entry for a particular destination address gives the address of a peer router capable of routing a packet to that particular destination address. The database is populated by peer routers updating the database with information concerning the destination address which the peer routers can reach. The database on the server is interrogated by the source router to learn the address of a destination peer router, and an encapsulated packet is then transmitted onto a connectionless network for transmission to the destination router. The peer-to-peer routing protocol may be DLSw protocol. The database may be maintained in accordance with the X.500 directory standard. The database may be interrogated using the lightweight data access protocol (LDAP).

Directory services caching for network peer to peer service locator

The invention provides a control mechanism that enables a destination router to authenticate response time requests issued by a source router before providing the requests to service software for processing. The control mechanism comprises a Network Endpoint Control Protocol (NECP) message format that is exchanged between the source and destination routers when measuring response time throughout the network. The NECP message format encapsulates a Command Length Status Data (CLSD) message that actually holds the response time requests. A collector router issues a novel control message to a responder router over a default responder port. If the responder is enabled for encryption communication, it will decrypt the control message according to the specified key and algorithm. If the responder is not so configured, it will check a conventional ACL to determine whether the client is authorized to communicate with the server. If permitted, the responder then responds to the collector in a manner dependent upon the particular protocol. In the case of a request to enable a UDP port for a particular time period, the responder processes a request and then sends back an acknowledgment to the collector. The collector receives the acknowledgment and then sends out a UDP probe packet to the responder. The responder then &ldquo;echoes&rdquo; the packet back to the collector, which keeps the result.

Protocol to coordinate network end points to measure network latency

A complete management system for specialized routers such as, for example, DLSw routers is provided. The management system uses a server to maintain a DLSw Directory, for example an LDAP directory. Whenever a DLSw router is booted, the DLSw router sends a registration message to the Server giving the network address of the DLSw router. The Server then maintains a directory of all DLSw routers in the network (the DLSw Directory). The information maintained in the DLSw Directory has the network address of each DLSw router, as received when the router is booted up. Also, at later times, the DLSw router sends a message to the DLSw Directory giving further information about the DLSw router. The further information comprises data such as: the types of encapsulation being received and routed by the router, etc.

Directory services network management locator

A transparently-bridged wide area network connecting Ethernet/IEEE 802.3-based local area networks uses redundant proxy devices on each LAN for internetwork communications. The proxy devices on a given LAN, implemented as data link switching (DLSw) devices, identify amongst each other a master proxy device for mediating services to be provided to an end station on the local area network. Each proxy device connected to the local area network sends a request to the identified master proxy device in response to detecting a frame transmitted by an end station on the local area network, for permission to establish a circuit connection for transfer of the frame via a wide area network. The master proxy device, based on prescribed criteria, selects one of the proxy devices for transferring the frame, and sends a grant response to the selected proxy device. The master proxy device sends an 'inuse' response as a denial response to the other proxy devices indicating the corresponding request has been denied, thereby avoiding contention for proxy services. Databases within the proxy devices track the request, grants, and denials to minimize generation of repeated requests. The inventory of granted requests may also be modified based on failures detected within the master proxy device, or any proxy device having received grants. Hence, redundant DLSw-type proxy devices may be implemented on a local area network while maintaining a stable and a robust communications system.

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Freemont, CA, United States of America

John Lautmann