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Category Archives for "Networking"

Just for fun: I love Junos in OP Script

A simple op script, just for fun. Next blog post will be more serious :) FOR TERMINAL : 24 Rows / 80 Columns / font: Courrier New 10 The video can see here : The 'op' script is called lovejunos.slax. It has been tested with release 11.4. You can simply...

Cisco Live 2012 San Diego

That was it! My work life has an absolute peak every year and that’s when I’m again fortunate enough to visit Cisco Live in the US. This year it was held in San Diego, California.
I flew in on Saturday with 2 colleagues on LA and drove to San Diego after a quick tour around Sunset Boulevard ;)

We stayed at the Manchester Grand Hyatt, which is a hotel I can truly recommend when visiting San Diego. Services were good and staff was helpful!

My focus this year was to combine both Datacenter and Service Provider sessions as those are the fields I’m active in. I found that the SP related sessions had a quite smaller crowd attending them. I guess this is related as the SP customers are considered important customers and get a lot more attention from Cisco people, so they already know what to expect in terms of roadmap and technologies. Still I had quite some very good sessions where I learnt about the features (and limitations) about some cool new things :-)

Sunday
On Sunday it’s a special day as you need to purchase additional sessions called Techtorials. This was the first year I took a Continue reading

CCIE Datacenter techtorial notes

The CCIE Datacenter techtorial was a very good session giving a good overview about the contents of the exam. I will not focus on the technologies in this article, but only on the specifics that I wrote down during the session. This means you will only find details about the exam and not about the technologies.
There are enough resources to find details about the technologies, but you are reading this article if you want to know what to find when you step into the testing center or the lab.

The session was presented by 3 guys, I would specifically mention Walid Issa who is the product manager for this particular CCIE track. Walid is a very nice guy and if you want to know something about the lab, ask him!

Written
Over 200 took the written beta already. it’s expected that a lot more people will take the DC written beta during Cisco live San Diego.

The Written is an overview of technologies with a medium to hard level. As all other written exams for CCIE the focus is on theory and not on configuration. When you know the technologies you should be able to pass.

Lab

Sample topology Continue reading

Packets of Interest 2012-06-12 — OSPF Refresher

I was recently brushing up and refreshing my OSPF knowledge and I discovered some great resources that I wanted to document for my future use and also share with others. I found these resources great for explaining/detailing area types, packet types, and neighbor states. This first document hosted at packetlife.net is one of the best explanations of packet types I've ever seen due to the visual aids that the author, Jeremy Stretch, incorporated.

How would you like to do IP Multicast without PIM or RP’s? Seriously, let’s use Shortest Path Bridging and make it easy!

 

Why do we need to do this? What’s wrong with today’s network?

Anyone who has deployed or managed a large PIM multicast environment will relate to the response to this question. PIM works on the assumption of an overlay protocol model. PIM stands for Protocol Independent Multicast, which means that it can utilize any IP routing table to establish a reverse path forwarding tree. These routes can be created with any independent unicast routing protocol such as RIP or OSPF, or even be static routes or combinations thereof. In essence, there is an overlay of the different protocols to establish a pseudo-state within the network for the forwarding of multicast data. As any network engineer who has worked with large PIM deployments will attest, they are sensitive beasts that do not lend themselves well to topology changes or expansions of the network delivery system. The key word in all of this is the term ‘state’. If it is lost, then the tree truncates and the distribution service for that length of the tree is effectively lost. Consequently, changes need to be done carefully and be well tested and planned. And this is all due to the fact that the Continue reading

Today is World IPv6 Launch Day!

After the success of last year’s World IPv6 Day, where success was measured with little to no problems reported, World IPv6 Launch Day has arrived! For a while major players like Google and Facebook had been white-listing their AAAA records to specific ISP recursive nameservers. This meant you had to query one of those in order to see IPv6 entries for their websites. Now that white-listing has been removed and all properly operating recursive nameservers will now serve up these records. They aren’t the only companies participating of course! Take a look at this list to see whom else signed up to promote their enabling of IPv6. Want some stats, take a look at the following:

But what does this mean to the non-techies out there? It is meant to be a passive change. You shouldn’t notice much in the way of interruptions. Perhaps your ISP will have a shorter route to a destination over IPv6, and you might get what you are trying to access a tiny bit quicker. If you like video/chat applications, this will soon mean that you’ll be Continue reading

The Best MPLS Lecture on the Net

The title says it all. Professor Karandikar gives two amazing lectures on MPLS and MPLS-TE that most engineers should hope to know cold. I watch it probably once every few months. Not saying much for my memory these days. It is an amazing amount of material delivered very precisely. Great stuff! I added some figures to […]

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Ethernet Switch Fabric Cards

I was working with a buddy today about switch fabric cards in the nexus 7000 and not doing a very good job at explaining it, so I figured I would draw some pictures. The conversation was around how adding more fabric cards increases the bandwidth. I think some, myself included growing up on Catalyst 6500’s […]

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Help Wanted: Cultural Change

This post is low on the nerdalert meter and more of the arts, rather than the science. Earlier this year, Level3 blogged about their new initiative of training ~%20 of their 11,000 person staff to be “change agents” in order to cross-pollinate their peers, the notion that change is healthy for the company (speculating). Change […]

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SDN and OpenFlow Quotes from some of the Best

Like anyone reading this, we are avid consumers (in my case leech) of information. I put together some quote from people regarding SDN and OpenFlow. Most of the people in the list are intrinsic in helping me shape my own views regarding technology with the outstanding content, ideas and research they generate. “Think of it as a […]

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Auto-RP and usage of "ip pim autorp listener"

After reading several forums with people arguing about what routers should be configured with the "ip pim autorp listener" command, I have decided to write this post explaining things in my own way (of course, with a lot of pictures, as usual).

MPLS VPLS configuration with Juniper JunOS.

Posting a Juniper VPLS how-to on a couple of J-series routers. Have been pretty SDN focused lately so wanted to get some real stuff in for a post. Docs on JunOS VPLS can be shaky so nothing like a couple real configs to plugin your address in the lab if having problems with L2 VPNs. […]

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The Fabric ERA

“Fabric” is a loosely used term, which today creates more confusion instead of offering direction. What exactly is a Fabric ? What is a Switch Fabric? Greg Ferro did a post here explaining how Ethernet helped the layer 2 switch fabric evolve. Sadly the use of switch fabric did not stop there. And this is […]
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