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Networking

iou2net.pl, an IOUlive replacement

September 22, 2011

In the months since Cisco IOU leaked out, many people have began using it for study purposes instead of or in addition to dynamips. One advantage that dynamips has over IOU is the ability to communicate with a physical network which comes in handy sometimes, like when you want to do pointless things like dumping […]

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LACP Between HP and Cisco Switches

August 12, 2011

Jennifer Huber posed a question on Twitter today: Does anyone have any opinion or pointers for HP Procurve 2900s? Had issues setting up LACP trunks w/c2960s, opted for single connections.. I thought I had written up how to configure LACP between HP and Cisco switches before, but after checking I realized that I didn’t. What […]

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How To Make Your Routers Reload Faster

July 22, 2011

When doing labs, one thing that really annoyed me was how long it took some of my routers to reload. After doing a lab exercise, I would always erase the configuration and reload in order to start from a “blank” configuration. I just recently discovered a way to speed up this process. It’s pretty basic […]

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HP: Changing the rules of networking

February 23, 2011

Yesterday, after having received zero help from the “HP Networking Global Competency Center” over the last three weeks, I managed to discover the cause of an issue I’ve been dealing with. I previously wrote “When isn’t a loopback always reachable?”, describing the issue. Since that time, I’ve loaded a “Premium License” (which costs $2,325.99 from […]

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When isn’t a loopback always reachable?

January 31, 2011

When it’s an HP ProCurve switch, of course! A long time ago I was taught that loopback interfaces are always up. HP’s Management and Configuration Guide for their 3500/5400/6200/6600/8200 switches seems to agree. Matter of fact, it says so right here in Chapter 8: User-defined loopback addresses provide the following benefits: A loopback interface is […]

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Bypassing the Internet Kill Switch

January 30, 2011

Nearly 100 years ago, in the middle of the Atlantic, Jack Phillips began sending out CQD, the international distress signal, over wireless. Phillips was a wireless operator aboard the RMS Titantic which had struck an iceberg a couple of hours earlier. Since then, radio has been responsible for saving countless lives and providing information and […]

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Example Cisco IOU Topology

January 21, 2011

Here’s an example topology for Cisco IOU to help you get started: In this example, SF is an IOU instance running on host “solaris”. IOUlive is also running on this host, bridging SF’s Ethernet0/0 interface to my physical network (and to the world). SJ1, SJ2, and SJ3 are IOU instances running on host “helium”. The […]

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Cisco IOU FAQ

January 18, 2011

I’ve received a lot of blog comments and e-mails since I first posted about Cisco IOU, so I have put together this comprehensive list of frequently asked questions to help alleviate some of that. Preface This list of frequently asked questions has been compiled in response to an overwhelming number of requests for information about […]

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Creating a NETMAP file for IOU

January 9, 2011

Those of you who use Dynamips and Dynagen are familiar with the .net files that are necessary for the virtual routers to interoperate (example). Cisco IOU also uses a file, named “NETMAP” to describe the virtual topology. Here’s a simple NETMAP file: 101:0 101:18 102:2 102:0 There are two routers represented here, identified by “application […]

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Comcast #fail

October 27, 2010

I received the following e-mail (only slightly censored): My friend’s mom runs a small business … and got Comcast business Internet hooked up earlier this week. From what I gathered from my friend, Comcast installed a Netgear router, in addition to the router that they already had in place there. Apparently when Comcast activated their […]

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