What is 2^128?
IPv6 introduces a 128 bit IP address for both source and destination address fields. This means that there are 2128 addresses possible with that many bits. 2128 = 340,282,366,920,938,000,000,000,000,000,000,000,000 I have long contended that I have no idea how to read that number. I usually say something like "a lot". But - thanks to one of my students (Thank You Bobby) the answer is now provided: "Three hundred forty undecillion, two hundred eighty two decillion, three hundred sixty six nonillion, nine hundred twenty octillion, nine hundred thirty eight septillion." One word - WOW!
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Neighbor Discovery (ND) Table in IPv6 Windows Machines
A great question I was asked in class was: "If Neighbor Discovery processes have replaced ARP in ICMPv6, how do you look at the quivalent of the ARP cache?" Great question. Here is the answer:
Here is a sample output (though I was not connected to an IPv6 network):
Hope that helps!
What is the LISP protocol?
Part of the answer is in your question: it is a protocol, and it stands for Locator/ID Separation Protocol. The use of LISP is targeted at deployment of virtual systems, and the movement/management of those systems/resources (such as Virtual Machines) across networks to other places such as other data centers. LISP really answers the question a customer might ask: how can I elastically and dynamically move, manage, and adjust compute services across multiple data center locations? The LISP protocol allows for workload mobility across physical locations, and this is not an easy task. Having the ability to move end systems such as VMs means you have to manage IP addresses to create flexible cloud resources. This has been a classical mobility problem in IP that has been solved with clever IP address management, or IP Mobility solutions. Let me spend a second defining the issue with IP. An IP address has 2 parts: a network part (IPv4) or prefix (IPv6), and a Host part (IPv4) or interface part (IPv6). We could redefine these as a "location" and an "end point". A more colloquial way would be to say a street name and a house number. So when we move the host or interface and connect to a different router it is likely that the network part, or location is going to change. There are exceptions to this, of course. For example if I am attached to my home network with a configured IP address of 192.168.1.175/24, I will almost certainly be able to connect to your home network and not change my IP address. I can also use IP mobility to manage my movement as well. What LISP does is it provides a scalable real world solution to this issue for large scale VM movement across networks where we know the location is changing for a given end point. LISP does this by creating a database (like a DNS that maps names to IP Addresses) that maps IP addresses of end points to IP addresses of locations. So what we get is:
There are essentially three components to the LISP enabled network:
You can get much more detail here: http://lisp.cisco.com/ What is Software Defined Networking?
It is not possible to give a one sentence answer to this great question. But I will answer it - take a deep breath: In a nut shell, Software Defined Networking, or SDN, is a network manager defined and network manager controlled way to implement networking solutions and configurations for applications, workloads, and services that is focused on scalable, virtualized and non-virtualized environments. Think of SDN as a layer of management that is wedged between todays control and management planes. OpenFlow is an implementation of SDN. OpenFlow is a communications protocol that uses network centric and aware intelligence. OpenFlow works on controllers placed in the network (they can be in switches and routers, or as stand alone devices) that enable programmability - or software definition. For example, OpenFlow on controllers can create network slices (subnetworks) to be used for particular applications or workloads. One can imagine a network slice to be used for a particular video collaboration meeting. Thus, like VMware has abstracted bare metal servers so multiple Operating Systems can run as Virtual Machines simultaneously and more efficiently on an underutilized physical server, OpenFlow abstracts the network routers, switches, and infrastructure so services and applications can be provided simultaneous network connectivity, privacy, and performance better utilizing the physical network capacity. SDN, then, is the virtualization of the network. OpenFlow controllers discover the network topology and the inventory of links as well as information within the network nodes (route tables, addresses, etc.). Network Administrators define policies and services within the OpenFlow configuration and programmability. A packet is received by the network. If there is no prior knowledge associated with the packet, the receiving node sends a message to the OpenFlow controller. If the controller determines, based on programmability and policy, that the packets should be accepted, the controller modifies the node tables and configurations such that the packet receives the appropriate service. This can include multiple nodes, as well as more information including oath configuration, QoS information, and much more. I hope that helps you to understand a little more about what a Software Defined Network is. What is Cisco ONE and Cisco OnePK?
Great questions! I think the best way to answer the question is to describe what each one is. I will start with Cisco ONE. Cisco ONEONE stands for "Open Network Environment". The idea is to allow programmability of the network and the network elements. This allows for consistency across both physical and virtual network environments. The way that Cisco ONE accomplishes this is to bring the Open Networking Foundation works together with the following tool sets:
So Cisco ONE is Automation and Orchestration of the network to meet various application requirements. You can see that OnePK is part of the Cisco ONE ecosystem. Now let's talk more specifically about OnePK. Cisco OnePKConsider the following customer problem: How can I have new ways to control/program/configure my network and its elements to meet application specific requirements? What OnePK (One Platform Kit) does is provide a rich and programmable service set APIs (Application Programmable Interfaces) to create a set of tools that can control the network infrastructure. This means that the new network engineer can write a C or Java program that can manipulate:
They write the program and OnePK provides a seamless interface to all Cisco operating systems NX-OS, IOS-XR, and/or IOS via consistency in verb usage. So the new network engineer does not worry about syntax and CLI. OnePK then becomes an interface like Visual Basic does when used in Excel or another analogy would be macros in Word. The routers and switches become programmable devices and OnePK transcends the need to manage each individual device. Check out the following demo: Some folks get confused between OnePK and OpenFlow. OnePK is an API, whereas OpenFlow is a protocol. I hope that demystifies the difference between those two. I further hope that the definitions of Cisco ONE and OnePK clearly define how they are related and how they are different things. Here are some links: http://www.cisco.com/en/US/prod/iosswrel/onepk.html For developers: http://www.cisco.com/en/US/prod/collateral/iosswrel/content/at_a_glance_c45-708540.pdf
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