Lionel L Florit

US Patent:

7911938, Mar 22, 2011

Filed:

Jan 20, 2006

Appl. No.:

11/336704

Inventors:

Lionel Florit - Greenbrae CA, US
Robert W. Klessig - Los Altos Hills CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04J 1/16

US Classification:

370216

Abstract:

Various systems and methods for preventing loops in the presence of control plane failures are disclosed. For example, one method involves sending a special data packet in response to detection of a break in a network loop and then unblocking a port if the special data packet fails to circumnavigate the network loop. Prior to detection of the break, the port was blocked by a loop prevention protocol, such as a spanning tree protocol. If the special data packet successfully circumnavigates the network loop, the port will not be unblocked.

US Patent:

7969980, Jun 28, 2011

Filed:

May 4, 2004

Appl. No.:

10/838882

Inventors:

Lionel Florit - Greenbrae CA, US
Robert W. Klessig - Los Altos Hills CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/28
H04L 12/56
G06F 15/173

US Classification:

370390, 370409, 370432, 709238

Abstract:

Methods and systems for distributing multicast messages in a network are disclosed. The use of such a method or system in an Ethernet network can result in a reduction in the number of flooded multicast messages. One method can involve receiving a companion message, which includes a multicast address, at a network device and extracting the multicast address from the companion message. The multicast address can then be associated with a VLAN and an interface of the network device. Another method involves receiving a join message, which identifies a multicast group being joined, and generating a companion message corresponding to the join message. The companion message includes an address of the multicast group.

US Patent:

8050183, Nov 1, 2011

Filed:

May 6, 2005

Appl. No.:

11/124462

Inventors:

Lionel Florit - Greenbrae CA, US
Robert W. Klessig - Los Altos Hills CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/26

US Classification:

370248, 370241, 370242, 370249, 370252

Abstract:

In some ring protocols, control messages are exchanged among ring nodes in order to implement certain behaviors, such as loop-free behavior and/or failure recovery, within the ring. A segment of a ring can be replaced by another network, effectively turning the ring into a daisy chain. If the intervening network does not allow transmission of the control messages used by the ring protocol, certain control messages may be blocked, causing the ring to operate in undesirable ways. Reflector ports can be implemented at each end of the daisy chain in order to prevent these control messages from being blocked.

US Patent:

8111634, Feb 7, 2012

Filed:

Aug 15, 2006

Appl. No.:

11/504941

Inventors:

Lionel Florit - Greenbrae CA, US
Robert W. Klessig - Los Altos Hills CA, US
Francois E. Tallet - Santa Clara CA, US
Pauline Shuen - Palo Alto CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/28

US Classification:

370258, 370403

Abstract:

Various systems and methods for integrating ring-protocol-compatible devices into network configurations that also include non-ring-protocol-compatible devices are disclosed. One such method, which can be performed by a network node that supports a ring protocol, involves generating a ring protocol packet and sending that ring protocol packet to a neighboring node. The ring protocol packet includes information, and the presence of this information within the packet causes a network device that receives the ring protocol packet to drop the ring protocol packet unless the network device supports a ring protocol. The information can include a reserved address (e. g. , in the destination address field of the packet) as well as a ring protocol identifier.

US Patent:

8270314, Sep 18, 2012

Filed:

Dec 29, 2009

Appl. No.:

12/648917

Inventors:

Norman William Finn - Livermore CA, US
Lionel Florit - Greenbrae CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/26

US Classification:

370252

Abstract:

An endpoint for determining a frame loss ratio is provided. The endpoint includes a processor and a memory coupled with the processor. The memory stores instructions that are executable to generate a number of synthetic frames, and insert the number of synthetic frames into a stream of data frames, the synthetic frames being transmitted to a responder endpoint address designated in the synthetic frames. The memory may also store instructions that are executable to determine a number of lost synthetic frames; and calculate a synthetic frame loss ratio as a function of the number of lost synthetic frames and the number of synthetic frames inserted into the stream of data frames.

US Patent:

8274919, Sep 25, 2012

Filed:

Sep 2, 2005

Appl. No.:

11/218886

Inventors:

Lionel Florit - Greenbrae CA, US
Robert W. Klessig - Los Altos Hills CA, US
Pauline Shuen - Palo Alto CA, US
Francois E. Tallet - Santa Clara CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/28

US Classification:

370256, 370405, 370452

Abstract:

Various systems and methods for implementing virtual ports within ring networks are disclosed. For example, one method involves allocating a logical port that corresponds to a first port and a second port and instantiating a spanning tree protocol instance. The first port and the second port are both assigned to a first ring network. The spanning tree protocol instance selectively blocks the logical port; however, the spanning tree protocol instance is unable to block the first port independently of blocking the second port. Events (e. g. , link failures and recoveries) that occur within the ring network are communicated to spanning tree by transitioning the state of the logical port in response to receiving a ring protocol control packet. The spanning tree protocol instance initiates a bridge protocol data unit (BPDU) exchange from the logical port in response to a transition in the state of the logical port.

US Patent:

8385215, Feb 26, 2013

Filed:

Nov 13, 2008

Appl. No.:

12/270563

Inventors:

Lionel Florit - Greenbrae CA, US
Jose A. Liste - Sunnyvale CA, US
Samer M. Salam - Vancouver, CA

Assignee:

Cisco Technoogy, Inc. - San Jose CA

International Classification:

G01R 31/08
G06F 11/00

US Classification:

370248

Abstract:

A method is provided in one example embodiment and includes generating a test port in a network environment, positioning the test port on a network element, associating the test port with a bridge domain, and configuring a maintenance point (MP) on the test port. The method further includes using the MP on the test port for connectivity fault management (CFM) operations at a test level.

US Patent:

8411690, Apr 2, 2013

Filed:

Feb 27, 2007

Appl. No.:

11/711294

Inventors:

Lionel Florit - Greenbrae CA, US
Robert W. Klessig - Los Altos Hills CA, US
Francois E. Tallet - Santa Clara CA, US

Assignee:

Cisco Technology, Inc. - San Jose CA

International Classification:

H04L 12/28
H04L 1/22

US Classification:

370401, 370218, 370242, 370255

Abstract:

Various systems and method of preventing data traffic connectivity between endpoints of a network segment are disclosed. One method involves receiving a segment protocol message from a first segment port within a network segment, which includes a plurality of network devices. In response to receipt of the segment protocol message, which can indicate whether connectivity is present between the segment endpoints via the network segment, a second segment port can be operated in a blocked state. Operating the second segment port in the blocked state prevents data plane connectivity via the network segment.