[SDN Protocols] Part 5 – NETCONF

This entry is part 6 of 6 in the series SDN Protocols

For those that followed my SDN Protocols series last summer, you might have noticed a missing entry: NETCONF. This protocol has actually existed for some time (the original now-outdated specification was published in 2006), but is appearing more often, especially in discussions pertaining to network automation. The current, updated specification – RFC6241 - covers a fairly large amount of material, so I will attempt to condense here.

NETCONF operates at the management layer of the network, and therefore plays a role similar to that of OVSDB. This is in contrast to protocols like OpenFlow  which operate at the control plane.

A key difference between NETCONF and other management protocols (including SNMP) is that NETCONF is built around the idea of a transaction-based configuration model. The NETCONF specification provides for some optional device capabilities aimed at assisting operators with the lifecycle of configuring a network device, such as rolling back a configuration upon an error. Unfortunately, not all network devices support such capabilities, but the protocol was built to make it easier to discover what kind of capabilities a network device can support.

 

Configuration Datastores

Before getting into the semantics Continue reading

Talk to the Dummy

dummyYou’ve hit brain freeze. It seemed like such a great idea at the time, but now that it’s 2am, the application is down, and you can’t find the problem, maybe it wasn’t after all. Or maybe it’s 4pm, and you’re sitting at your desk trying to figure out how to resolve a problem, or build a system. You’re completely stuck, and you’ve no idea what to do next.

In either case, it feels like you’ve researched every avenue, you’ve thought of every angle, you’ve gone over the problem time and time again, and your brain just can’t wrap around the problem any longer. You go back over the same material again and again, just trying to make sense of it.

You’ve hit brain freeze. What’s the solution?

Talk to the dummy.

No, I don’t mean your boss. And I don’t mean that person down the hall you think just doesn’t “get it.” We’ll cover that topic later. I mean, literally, the dummy. In the “old days,” there were software shops that would literally set aside an office for a dummy. There was a white board, a desk, and a dummy sitting behind the desk. Your job, as an engineer, Continue reading

Network Complexity

Network complexity plays a very important role during network design. Every network designer tries to find the simplest design. Although there is no standard definition for the network complexity yet, there are many subjective definitions. In today network designs decisions are taken based on an estimation of network complexity rather than absolute, solid answer. If… Read More »

The post Network Complexity appeared first on Network Design and Architecture.

Bitcoin in China still chugging along, a year after clampdown

A year after China began tightening regulations around Bitcoin, the virtual currency is still thriving in the country, albeit on the fringes, according to its largest exchange.Bitcoin prices may have declined, but Chinese buyers are still trading the currency in high volumes with the help of BTC China, an exchange that witnessed the boom days back in 2013, only to see the bust following the Chinese government’s announcement, in December of that year, that banks would be banned from trading in bitcoin.This eventually led to a clampdown that scared customers away from the currency, and threw a wrench in the business of local exchanges, including BTC China.To read this article in full or to leave a comment, please click here

The Upload: Your tech news briefing for Monday, March 30

Pebble Time breaks Kickstarter record with over $20 million raisedPebble won record support from the Kickstarter crowdfunding community in its second trip to the well, for its next-generation Pebble Time smartwatch, CNN Money reports. It raised $20.3 million from 78,463 people in a campaign ended Friday, making it the most-funded Kickstarter campaign ever by a $7 million margin. When it ships in May, the device will go up against the Apple Watch but offer a week between battery charges (rather than a day) and a lower price of $199.Tim Cook speaks out against “religious freedom” lawsTo read this article in full or to leave a comment, please click here

The Upload: Your tech news briefing for Monday, March 30

Pebble Time breaks Kickstarter record with over $20 million raisedPebble won record support from the Kickstarter crowdfunding community in its second trip to the well, for its next-generation Pebble Time smartwatch, CNN Money reports. It raised $20.3 million from 78,463 people in a campaign ended Friday, making it the most-funded Kickstarter campaign ever by a $7 million margin. When it ships in May, the device will go up against the Apple Watch but offer a week between battery charges (rather than a day) and a lower price of $199.Tim Cook speaks out against “religious freedom” lawsTo read this article in full or to leave a comment, please click here

New products of the week 03.30.2015

New products of the weekOur roundup of intriguing new products. Read how to submit an entry to Network World's products of the week slideshow.Flexiant ConcertoPricing: Until March 31, 2015, pay $15 a month to deploy and manage 10 concurrent virtual machines (VMs) in any supported cloud. For $65 a month, deploy and manage 50 concurrent VMs. To read this article in full or to leave a comment, please click here

Improving compression with a preset DEFLATE dictionary

A few years ago Google made a proposal for a new HTTP compression method, called SDCH (SanDwiCH). The idea behind the method is to create a dictionary of long strings that appear throughout many pages of the same domain (or popular search results). The compression is then simply searching for the appearance of the long strings in a dictionary and replacing them with references to the aforementioned dictionary. Afterwards the output is further compressed with DEFLATE.

CC BY SA 2.0 image by Quinn Dombrowski

With the right dictionary for the right page the savings can be spectacular, even 70% smaller than gzip alone. In theory, a whole file can be replaced by a single token.

The drawbacks of the method are twofold: first - the dictionary that is created is fairly large and must be distributed as a separate file, in fact the dictionary is often larger than the individual pages it compresses; second - the dictionary is usually absolutely useless for another set of pages.

For large domains that are visited repeatedly the advantage is huge: at a cost of single dictionary download, all the following page views can be compressed with much higher efficiency. Currently we aware Continue reading

Review: Portnox, Extreme lead NAC pack

Remember when network access control (NAC) was all the rage? Remember the competing standards from Microsoft, Cisco, and the Trusted Computing Group? Back around 2006, there were dozens of NAC products, many of which turned out to be buggy and difficult to implement. Over time, other network-based security products – mobile device management (MDM), intrusion prevention systems (IPS) and next-generation firewalls – came along and squeezed NAC into a narrower part of the market. But NAC hasn’t disappeared. In fact, NAC products have evolved and improved as well. For this review, we were able to bring the following five vendors together: Enterasys/Extreme Networks Mobile IAM, Hexis Cyber Solutions NetBeat NAC, Impulse Point SafeConnect NAC, Pulse Policy Secure, and Portnox NAC. (Cisco, ForeScout, Auconet, and Aruba declined our invitation.)To read this article in full or to leave a comment, please click here(Insider Story)

British Airways notifies frequent flyers of possible breach of their accounts

Over the last few days, a large number of British Airways customers have found that reward points they accumulated for flights, called Avios, have disappeared from their accounts. Others have been locked out of their accounts completely.Affected users have gathered on the flyertalk.com forum to share their experiences after calling the company’s call center, which according to reports, has been giving out “contradictory” information at times.It seems that the incident is the result of hackers gaining access to a large number of accounts.To read this article in full or to leave a comment, please click here

Cisco Live US – 2015

I will be attending this year’s Cisco Live US in San Diego!

This is my first Cisco Live, so I dont really know what to expect. There are alot of great sessions that I want to attend (if they are not already full), and I will be posting my week here when i have my sessions down.

If you want to connect for a coffee or a chat, feel free to drop me a mail/tweet, and im sure we can figure something out!

See you in San Diego!

Too Many Details Can Hurt You (or Why You Need the Fundamentals First)

The IPv6 Security Summit at the Troopers conference always has a few awesome IPv6 presentations (many people claim Troopers is the conference to attend if you’re serious about IPv6), and this year was no exception. A day after the MLD bashing, Enno Rey delivered a great in-depth presentation on DHCPv6 features and shortcomings.

It seems the DHCPv6 intricacies presented in that talk were too much for some of the attendees – that afternoon I accidentally stumbled upon a visibly distressed gentleman who started our chat with “How could anyone expect us to deploy IPv6 in a production environment?”

Read more ...

GitHub recovering from massive DDoS attacks

Software development platform GitHub said Sunday it was still experiencing intermittent outages from the largest cyberattack in its history but had halted most of the attack traffic.Starting on Thursday, GitHub was hit by distributed denial-of-service (DDoS) attacks that sent large volumes of Web traffic to the site, particularly towards two Chinese anti-censorship projects hosted there.Over the next few days, the attackers changed their DDoS tactics as GitHub defended the site, but as of Sunday, it appears the site was mostly working.A GitHub service called Gists, which lets people post bits of code, was still affected, it said. On Twitter, GitHub said it continued to adapt its defenses.To read this article in full or to leave a comment, please click here

[SDN Protocols] Part 5 – NETCONF

For those that followed my SDN Protocols series last summer, you might have noticed a missing entry: NETCONF. This protocol has actually existed for some time (the original now-outdated specification was published in 2006), but is appearing more often, especially in discussions pertaining to network automation. The current, updated specification - RFC6241 - covers a fairly large amount of material, so I will attempt to condense here. NETCONF operates at the management layer of the network, and therefore plays a role similar to that of OVSDB.

[SDN Protocols] Part 5 – NETCONF

For those that followed my SDN Protocols series last summer, you might have noticed a missing entry: NETCONF. This protocol has actually existed for some time (the original now-outdated specification was published in 2006), but is appearing more often, especially in discussions pertaining to network automation. The current, updated specification - RFC6241 - covers a fairly large amount of material, so I will attempt to condense here. NETCONF operates at the management layer of the network, and therefore plays a role similar to that of OVSDB.

[SDN Protocols] Part 5 – NETCONF

For those that followed my SDN Protocols series last summer, you might have noticed a missing entry: NETCONF. This protocol has actually existed for some time (the original now-outdated specification was published in 2006), but is appearing more often, especially in discussions pertaining to network automation. The current, updated specification - RFC6241 - covers a fairly large amount of material, so I will attempt to condense here. NETCONF operates at the management layer of the network, and therefore plays a role similar to that of OVSDB.

OS X – Outlook Search “No Results”

The worst feeling for a geek:

Courtesy of xkcd (http://xkcd.com/979/)

This has happened to me twice now: upgrading Mac OS X from one release to another and after the dust settles, the search function in Outlook 2011 totally breaks and always returns “no results”. As we all know, email sucks and being able to deftly search through that mound of crap in your mail client is the only thing that makes it somewhat bearable.

When I upgraded from 10.8 to 10.9, I was the guy in the cartoon above. I had to resort to uninstalling and reinstalling all of Office to get this repaired. Urgh.

Well, I just upgraded from 10.9 to 10.10 and lo, the same problem with Outlook search. However this time my karma must be right topped off because I found the solution buried in a message board after an hour or so of searching.

Sweet, merciful help!

Sweet, merciful help!

The post is from the macrumors.com forum and exactly described the issue and how to fix it on my machine. As stated, the permissions on my Microsoft Office 2011 directory allowed only my account to open the directory:

jknight@mac:~% ls -ld /Applications/Microsoft Office  Continue reading

2016 CCDE Practical Exam Dates

Cisco announced 2016 CCDE Practical exam dates. CCDE practical exam is organised only in every 3 months. Prerequisite for the exam is CCDE Written Qualification exam. You can attend the exam 4 times a year in  a Professional Pearson Centers. I am planning to start my CCDE trainings  2 months before an announced exam date… Read More »

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