Useful OpenFlow Resources

I wrote a post a while back introducing OpenFlow, and I informed you of my thoughts concerning this relatively new technology. Regardless of your need for a programmable network, the concept is certainly interesting and warrants some tinkering. It’s important to remember that OpenFlow itself is just a protocol definition, and until recently, there wasn’t a lot of software available that implemented it, and thus, no in-home tinkering. I’d like to point out a few new projects that are implementing OpenFlow and making it relatively easy to implement on your own.

IPv6 Prefix Lengths

For years, discussions regarding the appropriate prefix length for IPv6 subnets have been waged, with high profile organizations and bloggers chipping in their $0.02 for all kinds of opinions. IPv6 enthusiasts have long-adhered to their “A /64 for every subnet” approach, and they give many good reasons for this approach. There are others who recognize the sheer amount of waste from this method, and suggest much more restrictive prefixes, such as /126 for a point-to-point link, as that prefix allocates 2 addresses, identical to the /30 mask in the IPv4 world.

IPv6 Prefix Lengths

For years, discussions regarding the appropriate prefix length for IPv6 subnets have been waged, with high profile organizations and bloggers chipping in their $0.02 for all kinds of opinions. IPv6 enthusiasts have long-adhered to their “A /64 for every subnet” approach, and they give many good reasons for this approach. There are others who recognize the sheer amount of waste from this method, and suggest much more restrictive prefixes, such as /126 for a point-to-point link, as that prefix allocates 2 addresses, identical to the /30 mask in the IPv4 world.

Preparation Tips for the JNCIE-SEC Exam

Not a day that goes by since having passed the JNCIE-SEC exam that I don't receive an inquiry in one form or another regarding how I prepared for the exam.  It seems that there is an incredible amount of interest in this exam, especially from all those die-hard ScreenOS folks that are now converting to Junos.  So instead of constantly repeating myself, I figured I'd just put it up on the blog so others can benefit (leaving me more time to do other things, 'heh).

NOTE: For full disclosure, I must reveal that I am an Technical Trainer and Certification Proctor at Juniper Networks.  As such, I take EXTRA responsibility towards protecting the content and integrity of the exam and I take the certification credentials very seriously.  Not only that, I worked REALLY, REALLY hard to achieve my JNCIE certifications, and I believe everyone else should too! As such, I kindly ask that candidates refrain from asking me questions which would be considered a violation of the NDA.  Also, I should add that although I work for Juniper, the viewpoints expressed in this article are my own and may not necessarily be shared by my Continue reading

IPv6 Hacking – “thc-ipv6” [Part 2]

A while back I did a post called IPv6 Hacking - “thc-ipv6” Part 1 - it was, in fact, the first post here on Keeping It Classless. That post focused on the flood_router6 script, which unleashed a flood of IPv6 Router Advertisements (RAs) on a layer 2 network segment, bringing vulnerable operating systems like Windows 7 to their knees. The “fake_router6” script is another member of the “thc-ipv6” suite that grants a powerful weapon to a would-be attacker.

IPv6 Hacking – “thc-ipv6” [Part 2]

A while back I did a post called IPv6 Hacking - “thc-ipv6” Part 1 - it was, in fact, the first post here on Keeping It Classless. That post focused on the flood_router6 script, which unleashed a flood of IPv6 Router Advertisements (RAs) on a layer 2 network segment, bringing vulnerable operating systems like Windows 7 to their knees. The “fake_router6” script is another member of the “thc-ipv6” suite that grants a powerful weapon to a would-be attacker.

IPv6 Hacking – “thc-ipv6” [Part 2]

A while back I did a post called IPv6 Hacking - “thc-ipv6” Part 1 - it was, in fact, the first post here on Keeping It Classless. That post focused on the flood_router6 script, which unleashed a flood of IPv6 Router Advertisements (RAs) on a layer 2 network segment, bringing vulnerable operating systems like Windows 7 to their knees. The “fake_router6” script is another member of the “thc-ipv6” suite that grants a powerful weapon to a would-be attacker.

Configuring OSPF Between Vyatta and Cisco IOS

This is a guide to configuring OSPF between Cisco IOS and the open-source Vyatta router platform. I was able to do all of this on my desktop PC, by running Cisco IOS in GNS3 and Vyatta as a virtual machine. I used the guide here to bridge both virtual routers together, so that communication could be established. The Cisco side was pretty straightforward. I configured the FastEthernet interface and enabled OSPF on it:

Configuring OSPF Between Vyatta and Cisco IOS

This is a guide to configuring OSPF between Cisco IOS and the open-source Vyatta router platform. I was able to do all of this on my desktop PC, by running Cisco IOS in GNS3 and Vyatta as a virtual machine. I used the guide here to bridge both virtual routers together, so that communication could be established. The Cisco side was pretty straightforward. I configured the FastEthernet interface and enabled OSPF on it:

OSPF Won’t Redistribute My Static Routes!

I was working on some CCNP ROUTE labs, and I was attempting to rebuild a basic OSPF lab from memory. The lab included practice with inter-area route summarization, and static route redistribution. I ran across a problem that seems to be plaguing others, at least according to google, but my searches didn’t yield a solution to my specific problem, which was that the static routes I had created weren’t being redistributed by OSPF.

OSPF Won’t Redistribute My Static Routes!

I was working on some CCNP ROUTE labs, and I was attempting to rebuild a basic OSPF lab from memory. The lab included practice with inter-area route summarization, and static route redistribution. I ran across a problem that seems to be plaguing others, at least according to google, but my searches didn’t yield a solution to my specific problem, which was that the static routes I had created weren’t being redistributed by OSPF.

The Global Internet Speedup (NOT)

I recently saw posts from a few sources on a new initiative backed by a consortium that includes Google and OpenDNS to attempt to improve the overall speed of the internet by optimizing the way DNS works on the internet. If you think about it, a great deal of internet traffic is high-volume requests for things like photos, music, video, and the like. You may know, then, that content providers like Akamai have positioned themselves globally around the world to provide this content at a relatively close physical location to those requesting it.

The Global Internet Speedup (NOT)

I recently saw posts from a few sources on a new initiative backed by a consortium that includes Google and OpenDNS to attempt to improve the overall speed of the internet by optimizing the way DNS works on the internet. If you think about it, a great deal of internet traffic is high-volume requests for things like photos, music, video, and the like. You may know, then, that content providers like Akamai have positioned themselves globally around the world to provide this content at a relatively close physical location to those requesting it.

New Feature – Keeping It Classless LABS

I’m pleased to announce a new feature on the site. I’m going to start publishing some articles on more fundamental concepts in networking in the form of video walk throughs / labs. I wanted to free up the main blog feed for some more advanced topics, and a lot more of an overall network design discussion, as well as the occasional fun stuff. Several people have approached me in the past about making something like this that would help beginners learn the fundamentals, and at the time I wasn’t able to, but I feel like I’m able to do them now.

Keeping It Classless Labs – Static Routing

This is the first in what I hope to be a useful series on configuration/walk through videos aimed at educating up-and-coming networking professionals on some of the more fundamental concepts. Today we’ll be looking at static routing and how to configure it in a small Cisco network. Below are the lab files (GNS3) and the videos themselves. Download the Lab Outline Download the GNS3 Lab used in this video Since it’s a new Youtube channel, I’m limited to 15 minutes per clip, and therefore had to break it into two parts.

New Feature – Keeping It Classless LABS

I’m pleased to announce a new feature on the site. I’m going to start publishing some articles on more fundamental concepts in networking in the form of video walk throughs / labs. I wanted to free up the main blog feed for some more advanced topics, and a lot more of an overall network design discussion, as well as the occasional fun stuff. Several people have approached me in the past about making something like this that would help beginners learn the fundamentals, and at the time I wasn’t able to, but I feel like I’m able to do them now.

Keeping It Classless Labs – Static Routing

This is the first in what I hope to be a useful series on configuration/walk through videos aimed at educating up-and-coming networking professionals on some of the more fundamental concepts. Today we’ll be looking at static routing and how to configure it in a small Cisco network. Below are the lab files (GNS3) and the videos themselves. Download the Lab Outline Download the GNS3 Lab used in this video Since it’s a new Youtube channel, I’m limited to 15 minutes per clip, and therefore had to break it into two parts.

New Feature – Keeping It Classless LABS

I’m pleased to announce a new feature on the site. I’m going to start publishing some articles on more fundamental concepts in networking in the form of video walk throughs / labs. I wanted to free up the main blog feed for some more advanced topics, and a lot more of an overall network design discussion, as well as the occasional fun stuff. Several people have approached me in the past about making something like this that would help beginners learn the fundamentals, and at the time I wasn’t able to, but I feel like I’m able to do them now.
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