Cisco Technology, Inc.

Chengelpet Ramesh

Ming Zhang

Shyam N Kapadia

Nilesh Shah

Umesh Mahajan

Marco Di Benedetto

Ramana Mellacheruvu

Vamsidhar Valluri

Michael Wu

Pritam Shah

Anusankar Elangovan

Rajesh Babu Nataraja

Hei Tao Fung

Alagu Annaamalai

Ramesh M Santhanakrishnan

Sridhar Aswathnarayan

Wafo L Tengueu

Yaonan Liang

Mrinal Baruah

Ganesh P Murthy

Sankararaman Jayaraman

A distributed neighbor discovery module is disclosed where all neighbor discovery operations and functionalities may be distributed to a switch device processor. Each neighbor discovery process on a switch device may run as an individual neighbor discovery router node. There may be no coordination between neighbor discovery processes occurring on different switch devices. All other traffic, including both IPv6 control traffic and data traffic destined to the router may be processed by the central controller processor.

Neighbor discovery for IPV6 switching systems

Some implementations provide a method for managing switches in a data center that includes: (1) establishing a connection from one switch to another switch in the data center, the data center providing a plurality of virtual local area networks (VLANs), each VLAN including at least one Virtual Machine and capable of spanning across more than one of the plurality of switches; (2) provisioning device prefixes for IPv6 addresses, a given device prefix corresponding to a particular VLAN on a particular switch in the data center, the given device prefix included in a host address of a particular virtual machine, the particular virtual machine hosted on a server computer, the sever computer connected to the particular switch without additional intervening switches; (3) configuring a hardware memory to include prefix information and address information; and (4) transferring packets by using the prefix information and the address information.

System and method for scaling IPV6 on a three-tier network architecture at a large data center

An example method for routing IPv6 link-local addresses in a network environment is provided and includes receiving a packet at a first switch from an attached first host in a virtual local area network (VLAN) associated with a virtual routing and forwarding (VRF) instance of a network environment, where the packet is destined to an Internet Protocol version 6 (IPv6) link-local address of a remote second host in the VLAN, and routing the packet at Layer 3 to a second switch, to which the second host is attached. In specific embodiments, the second switch routes the packet at Layer 3 to the second host if the VRF does not include duplicate IPv6 link-local addresses corresponding to the IPv6 link-local address of the second host; the second switch bridges the packet at Layer 2 to the second host if the VRF includes at least one duplicate IPv6 link-local address.

Routing internet protocol version 6 link-local addresses in a network environment

Techniques are provided for sending address information of virtual machines to a physical switch. A migration of a virtual machine to a physical server is detected. The physical server obtains address information of the virtual machine, and upon obtaining the address information of the virtual machine, the physical server sends the address information to a first physical switch that is connected to the physical server.

Optimizing handling of virtual machine mobility in data center environments

A method for optimizing within subnet communication in a network environment is provided and includes receiving, at a Top-Of-Rack (ToR) switch, an advertisement from an attached host belonging to a subnet of a network environment, seeking a Media Access Control (MAC) address of a remote host in the subnet, looking up a host information database in a control plane of the ToR switch, and responding to the advertisement with the MAC address of the remote host. If the MAC address is not found, the ToR switch may not respond to the advertisement. The method can further include receiving, at the ToR switch from a remote ToR switch in the subnet, a host information of the remote host in the subnet, including an IP address and the MAC address of the remote host, the Layer 2 broadcast domain it belongs to, and storing the host information in the host information database.

System and method for optimizing within subnet communication in a network environment

In one embodiment, a method includes receiving from a server, flow data for a plurality of flows at a network device, the flow data comprising for each flow, a destination address and a time indicating when a last packet was processed for the flow at the server, updating a flow table at the network device, identifying one of the flows in the flow table as an inactive flow, and removing a route for the inactive flow from a forwarding information base at the network device. An apparatus and logic are also disclosed herein.

Forwarding table optimization with flow data

System and method for scaling IPv6 on a three-tier network architecture at a large data center

In one embodiment, a method includes tracking at a network device in communication with a plurality of virtual machines, virtual machine movement based on a device identifier in a packet received from one of the virtual machines and storing location information for the virtual machine in a virtual machine move list at the network device. The location information from the virtual machine move list is inserted into a forwarding information base for use in optimized forwarding of packets destined for the virtual machine. An apparatus and logic are also disclosed herein.

Packet forwarding optimization with virtual machine mobility by comparing device identifiers to determine VM movement

Systems and methods are provided to detect when a virtual machine moves across a switch device boundary, keep existing application sessions alive, and provide optimal forwarding for new application sessions with graceful address migration. Virtual machine movement can be detected on the new switching device by comparing the Device ID in the Source Address of the ND-NA with the Device ID of the new switching device. A temporary hardware forwarding sub-optimal path is maintained for existing application sessions. A new IP address is assigned to the moved virtual machine and an optimal forwarding path is programmed in hardware for new application sessions. The temporary sub-optimal hardware forwarding path is removed after all old application are terminated.

Method of IPv6 at data center network with VM mobility using graceful address migration

An example method is provided and includes receiving, at an ingress switch in a network, a packet from an attached host that is coupled to a destination host, where the packet includes an Internet Protocol version 6 (IPv6) address of a destination host, comparing the IPv6 address with a plurality of entries in a longest prefix match (LPM) table, in which each entry includes a value string and a corresponding mask string configured to detect a match for a specific combination of a segment prefix and a switch-id in the IPv6 address, identifying an egress switch from a matching entry in the LPM table, and forwarding the packet to the egress switch. The IPv6 address includes a combination of segment prefix and switch-id associated with the egress switch. The segment prefix corresponds to an identifier of a network segment, and the switch-id corresponds to an identifier of a switch in the network.

System and method for scaling IPv6 addresses in a network environment

Distributed IPv6 neighbor discovery for large datacenter switching systems

A method for detecting a suspicious packet flow in a packet-switched network comprises the computer-implemented step of receiving a first packet in which the SYN bit but not the ACK or RST bit of the packet's TCP header is set. If a specified first time has elapsed, a packet counter associated with the destination address of the flow is incremented. A determination as to whether the packet counter is greater than a specified threshold values is made. If the packet counter is greater than the threshold value, a notification message is generated. In one embodiment, information identifying a packet flow is aggregated to an aggregation cache based on the destination address of the flow.

Detecting network denial of service attacks

A technique that may be used to limit the amount of flooding that occurs for a particular virtual local area network (VLAN) in a data network. Limits are established for VLANs processed by an intermediate node. Each limit indicates a number of forwarding database entries that may be associated with a particular VLAN. If the number of entries in the forwarding database reaches the limit established for a particular VLAN, an action is taken which may include limiting the amount of flooding that occurs for that VLAN.

Dynamic unknown L2 flooding control with MAC limits

A method and apparatus allows for continued operation of one or more applications running at a network device with reduced delay despite crashes or failures at that device. The network device includes two or more supervisor cards for running the applications and a plurality of line cards. According to the invention, one supervisor card is designated the active supervisor card and one supervisor card is designated the standby supervisor card. As changes in state and other operating conditions take place on the active supervisor events are generating for passing at least some of this information to the standby supervisor where it is stored. Following a crash or failure of the active supervisor card, the standby becomes the newly active supervisor card. The standby supervisor performs a consistency check with the line cards and resets those that fail the check. The standby supervisor also determines which data records and state information stored at the standby supervisor are valid, and begins running the applications loaded onto the device. Those data records and state information determined by the standby supervisor to be valid are utilized by the applications in continuing their operation, while invalid data records and state information are discarded.

Growing community of inventors

San Jose, CA, United States of America

Chengelpet Ramesh