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Free Cisco labs for CCNA, CCNP & CCIE !

Free Cisco labs for CCNA, CCNP & CCIE !
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ostinato - Packet/Traffic Generator and Analyzer GNS3 Labs :: Cisco Router Simulator Network Labs & Topologies For CCENT, CCNA, CCNP & CCIE Candidates! Packet Life Greyhole - Redundant Storage Pooling using Samba Cisco IOS Hints and Tricks: TRILL and 802.1aq are like apples and oranges A comment by Brad Hedlund has sent me studying the differences between TRILL and 802.1aq and one of the first articles I’ve stumbled upon was a nice overview which claimed that the protocols are very similar (as they both use IS-IS to select shortest path across the network). After studying whatever sparse information there is on 802.1aq (you might want to read Greg Ferro’s fascination with IEEE paywall) and the obligatory headache, I’ve figured out that the two proposals have completely different forwarding paradigms. To claim they’re similar is the same as saying DECnet phase V and MPLS Traffic Engineering are similar because they both use IS-IS. TRILL forwarding Within the backbone, TRILL is a true layer-3 protocol: TRILL header has a hop count, RBridges have layer-3 addresses and the layer-2 header changes as the packet is propagated across the backbone. 802.1aq forwarding The ingress PBB (Provider Backbone Bridge) takes the user’s MAC frame and encapsulates it in 802.1ah MAC frame.

GNS3 | Graphical Network Simulator Route Views Project Page Internetworking Technology Handbook From DocWiki Creating a PDF of the Internetworking Technology Handbook Create a PDF of the Internetworking Technology Handbook that you can save on your computer and print. Internetworking Basics An internetwork is a collection of individual networks, connected by intermediate networking devices, that functions as a single large network. The following articles provide information about internetworking basics: LAN Technologies A LAN is a high-speed data network that covers a relatively small geographic area. The following articles provide information different LAN technologies: WAN Technologies A WAN is a data communications network that covers a relatively broad geographic area and that often uses transmission facilities provided by common carriers, such as telephone companies. The following articles provide information about the various protocols and technologies used in WAN environments: Internet Protocols The following articles provide information about different IOS IP technologies: Routing

VirtualBox AAA and VTYs in IOS-XR : Bingo Continuing on the IOS-XR saga, this is the newest bunch of things that don't "work as expected" (© Cisco). Well, as expected by me, not by Cisco. Everything started while trying to configure a primary and backup aaa login method on an ASR9k, when i realized that... 1) having a backup aaa login method with the same tacacs servers as the ones in the primary aaa login method (which is using the management vrf) doesn't work Imagine the following aaa configuration: ! This is supposed to work in the following way: As long as at least one mgmt interface is up (i'm using a virtual-ip for the mgmt interfaces), tacacs communication should happen through the out-of-band mgmt interfaces. Guess what! In order to overcome the above problem, i thought of using different vty templates, each one with a different access method. ! Since the "rotary" command is not supported in IOS-XR, this is what you can do: ! And this is the point you realize that you can't choose a vty, because... So i tried the following: !

IPv6 Autoconfiguration - The Internet Protocol Journal - Volume 7, Number 2 Since 1993 the Dynamic Host Configuration Protocol (DHCP) [1] has allowed systems to obtain an IPv4 address as well as other information such as the default router or Domain Name System (DNS) server. A similar protocol called DHCPv6 [2] has been published for IPv6, the next version of the IP protocol. However, IPv6 also has a stateless autoconfiguration protocol [3], which has no equivalent in IPv4. DHCP and DHCPv6 are known as stateful protocols because they maintain tables within dedicated servers. However, the stateless autoconfiguration protocol does not need any server or relay because there is no state to maintain. This article explains the IPv6 stateless autoconfiguration mechanism and depicts its different phases. Every IPv6 system (other than routers) is able to build its own unicast global address. Address types have well-defined destination scopes: global, site-local and link-local. At minimum, a NIC is associated with a single link-local address.

ASR9000/XR: The concept of a SMU and managing them Introduction A SMU is a software maintenance update, or simply put a patch, that can be loaded on the XR device you are running. The concept of a SMU applies to all XR devices, although this article focuses on the ASR9000 primarily. When the system is running into a SW deficiency (a.k.a. a bug) Cisco can provide a patch for that particular problem in order for you to keep running your base release, but get free of the problem at hand. How do SMU’s work? A SMU is a patch that is provided on a per release and per component basis and is specific to the platform. SMU’s are “PIE” files (package installation envelope) similar as the functionality of feature PIE’s such as MGBL, MPLS and multicast and they are installed in a similar fashion. The 3 operation steps to apply a smu are: Addition of the smu to the filesystemActivation of the smu onto the systemCommitting the smu change so it is persistent across reloads Example smu installation and application Couple of notes to that: Info: ser 'root' •1.

The TCP/IP Guide The TCP/IP Guide Welcome to the free online version of The TCP/IP Guide! My name is Charles and I am the author and publisher. I hope you will find the material here useful to you in your studies of computing, networking, and programming. Here are a few tips, links and reminders to help you out: Introduction: Newcomers to The TCP/IP Guide may wish to read the Introduction and Guide to the Guide, which will explain what the Guide is about and provide you with useful information about how to use it. Last but definitely not least: this site is provided as an online reference resource for casual use. If you like The TCP/IP Guide enough to want your own copy in convenient PDF format, please license the full Guide. Thanks again and enjoy the site! Charles Home - Table Of Contents - Contact Us

Understanding ELAM With the increasing complexity of networking devices and protocols, it can be extremely difficult to pinpoint the source of a networking problem. Often we need to determine if a frame was received and forwarded correctly on a particular device. There are several capturing tools, debugs, and tricks available to help answer this question. However, not all are feasible or available to run on a production network. ELAM (Embedded Logic Analyzer Module) is an engineering tool that gives us the ability to look inside Cisco ASICs and understand how a packet is being forwarded. ELAM is “embedded” within the forwarding pipeline and can capture a packet in real time without affecting performance or control plane resources. Did the packet reach the forwarding engine? And much more… ELAM is extremely powerful, granular, and non-intrusive. ELAM was designed as a diagnostic tool for internal use. So, with such a firm disclaimer and challenges, why are we discussing ELAM now? ELAM Workflow Centralized vs.