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Taking the Old Approach to Cisco Live 2014

I was just reading through Bob’s blog post from today and wanted to give a rebuttal of sorts.  In his post, Bob tells us that’s he’s going to be at Cisco Live US in San Francisco this year but he won’t be coming on the Full Conference pass like he usually does.  He’s going with the Social Event pass this year, which is actually a great, great way to attend.  I know several people who are thinking about scaling back to the Social Event pass as well, and there’s nothing wrong with doing it like that.  There are some things that it doesn’t get you, though.

The Social Event pass means no breakout sessions.  These are the bread-and-butter of the conference and the real technical reason that I try to go each year (listen to me talk like I’m a 20-year NetVet…LOL).  Yes, most of the sessions are available on Cisco Live 365 afterwards, but that leaves two problems for me.  First of all, I will never actually make the time to go back and sit through these sessions after the event.  It’s just something that won’t happen with life and work and everything going on.  Secondly, I cannot sit Continue reading

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The Foundation of Network Programmability

Ever since I entered this field, I’ve been interested in this concept of “network programmability”. Forgetting for a second what we’ve been talking about in the past few years since the advent of the “SDN tsunami”, even the ability to automate simple infrastructure tasks at a small scale has grabbed my attention. It’s important to note something here; the CLI is a wonderful tool. So many vendors take the wrong approach and say the CLI is going away in lieu of pretty GUIs and APIs, as if someone can’t write a really good CLI to consume a really good API.

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The Foundation of Network Programmability

Ever since I entered this field, I’ve been interested in this concept of “network programmability”. Forgetting for a second what we’ve been talking about in the past few years since the advent of the “SDN tsunami”, even the ability to automate simple infrastructure tasks at a small scale has grabbed my attention. It’s important to note something here; the CLI is a wonderful tool. So many vendors take the wrong approach and say the CLI is going away in lieu of pretty GUIs and APIs, as if someone can’t write a really good CLI to consume a really good API.

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Ansible for Networking

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Taking a New Approach to Cisco Live 2014

It’s getting to be that time of year again when geeks across North America (and beyond) start getting excited for Cisco Live! The buzz is starting a bit early this year, but that’s because Cisco Live is about a month earlier this year (May 18-22) than it has been in recent years.

Introduction

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Show 184 – The Future of Networking Part 2 as Inspired by #NFD7

At Networking Field Day 7, the delegates were treated to vendor demonstrations that challenged our thinking about the future of networking. Perhaps the industry is not agreed on just how we’ll implement and operate our networks in the coming years, but one thing is for certain. The landscape will be different. In this and the previously […]

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The post Show 184 – The Future of Networking Part 2 as Inspired by #NFD7 appeared first on Packet Pushers Podcast and was written by Ethan Banks.

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Review: Hadoop Operations

Hadoop Operations Eric Sammer Hadoop is one of those applications all data centers seem to need to support – and there is a lot of information out there about how Hadoop works, how to use it, and how to build Hadoop systems. From these, it’s pretty easy to glean a general set of requirements for […]

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HP Comware-based Switches – Link Aggregation

The 3Com/HPN/H3C based Switches offers the utilization of interfaces such as Ethernet, Fast Ethernet, GigabitEthernet or TenGigabitEthernet. The Link Aggregation feature allows the gathering of many ports in order to increase the link’s velocity concerning the full duplex communication between the two devices.

In Link-Aggregation mode the ports are utilized in parallel, supporting the bandwith’s growth and expansion, without the need of buying an additional hardware.

For example, we can use four 100Mb ports in each device to form a communication between two switches using 400Mb among them. However, the utilization of redundant enlaces raises the possibility of loops within the network. Link Aggregation avoids the situation which the blocking state or loops, stop the gathered ports, treating them as one single interface. For the STP, SNMP and VLANs the interfaces are treated as one logical link.

Other name used for the Link Aggregation is EtherChannel.

The LACP protocol is part of the 802.3ad specification for Link Aggregation, allowing that switches and servers negotiate the port groups with different manufactures automatically. Both ports should offer constant support to the protocol, so that the Link Aggregation could work correctly.

Some Switch models can utilise the PagP (Cisco) protocol or interface Continue reading

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A Reappraisal of Validation in the RPKI

I’ve often heard that security is hard. And good security is very hard. Despite the best of intentions, and the investment of considerable care and attention in the design of a secure system, sometimes it takes the critical gaze of experience to sharpen the focus and understand what’s working and what’s not. We saw this with the evolution of the security framework in the DNS, where it took multiple iterations over 10 or more years to come up with a DNSSEC framework that was able to gather a critical mass of acceptance. So before we hear cries that the deployed volume of RPKI technology means that its too late to change anything, let’s take a deep breath and see what we've learned so far from this initial experience, and see if we can figure out what's working and what's not, and what we may want to reconsider.

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Packet Life Turns Six

Today marks Packet Life's sixth birthday, and I'm celebrating by launching the new site format I talked about in January. The relaunched site is hosted on an entirely new server from Linode, which means you can (finally) access packetlife.net via native IPv6! The entire code base has been rewritten on Django 1.6, and should feel lighter and more responsive. The layout has been rewritten as well using the Bootstrap CSS framework.

You might have noticed that some components of the old site are now gone: The discussion forums and wiki have been axed in favor of focusing more on the site's core content. The tools armory, which was initially in jeopardy, has been maintained in response to community interest (although I do intend to spend a good amount of time cleaning it up).

There are no doubt bits of code here and there that need a tweak or three, but generally speaking the site is up and running. If you do encounter an error, rest assured that I've been alerted and should have it fixed in little time. If you feel that something is terribly amiss, give me a shout on Twitter and I'll look into Continue reading

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Get Another Network Cert Or Learn More About DevOps?

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Quick Thoughts on the Micro Data Center

Here's something that's been on my radar lately: while all the talk in the networking world seems to be about the so-called "massively scalable" data center, almost all of the people I talk to in my world are dealing with the fact that data centers are rapidly getting smaller due to virtualization efficiencies. This seems to be the rule rather than the exception for small-to-medium sized enterprises.

In the micro data center that sits down the hall from me, for example, we've gone from 26 physical servers to 18 in the last few months, and we're scheduled to lose several more as older hypervisor hosts get replaced with newer, denser models. I suspect we'll eventually stabilize at around a dozen physical servers hosting in the low hundreds of VMs. We could get much denser, but things like political boundaries inevitably step in to keep the count higher than it might be otherwise. The case is similar in our other main facility.

From a networking perspective, this is interesting: I've heard vendor and VAR account managers remark lately that virtualization is cutting into their hardware sales. I'm most familiar with Cisco's offerings, and at least right now they don't seem to Continue reading

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Quick Thoughts on the Micro Data Center

Here's something that's been on my radar lately: while all the talk in the networking world seems to be about the so-called "massively scalable" data center, almost all of the people I talk to in my world are dealing with the fact that data centers are rapidly getting smaller due to virtualization efficiencies. This seems to be the rule rather than the exception for small-to-medium sized enterprises.

In the micro data center that sits down the hall from me, for example, we've gone from 26 physical servers to 18 in the last few months, and we're scheduled to lose several more as older hypervisor hosts get replaced with newer, denser models. I suspect we'll eventually stabilize at around a dozen physical servers hosting in the low hundreds of VMs. We could get much denser, but things like political boundaries inevitably step in to keep the count higher than it might be otherwise. The case is similar in our other main facility.

From a networking perspective, this is interesting: I've heard vendor and VAR account managers remark lately that virtualization is cutting into their hardware sales. I'm most familiar with Cisco's offerings, and at least right now they don't seem to Continue reading

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Secret CEF Attributes Part 6, The BGP Connection

In the first five parts of this series we covered all the steps necessary to distribute QoS and monitoring to a large backbone. I guess at this point I should mention that this technology has a name (and acronym, of course.) Cisco calls it QoS Policy Propagation through BGP (QPPB.) I hope these blog posts […]

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The post Secret CEF Attributes Part 6, The BGP Connection appeared first on Packet Pushers Podcast and was written by Dan Massameno.

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Mind the Gap

One of my pleasures of traveling is listening to the way people speak both with their dialects and their phrases. For those of you that have been to London and ridden “The Tube,” you know that familiar recording, “Mind the Gap.” After talking with several people at this year’s Open Networking Summit (ONS) this past week, I heard that same phrase in my head.

Why?

In this case, the “gap” is the chasm that early software defined networking (SDN) adopters have to cross to get started.  Because SDN is a new idea, crossing the gap represents being prepared to challenge old ideas about networking and even your own experiences.

If you really think about it, you don’t want to just mind the gap—you want to be careful not to fall into the old ways of thinking—but you want to cross that gap and keep moving forward. To do that from an open networking perspective, you have to create an opportunity and dig in, grab a controller and an SDN-ready switch and start hacking.

I had a fantastic discussion with a customer at the ONS week who had safely crossed the gap.  Let’s call him Joe. Joe is Continue reading

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TCP/IP over VXLAN Bandwidth Overheads

A recent ‘conversation’ around VXLAN encapsulation and MTU with Matt Oswalt got me thinking about this subject recently. My calculations were mostly wrong (Matt’s were not) and I also found a shocking amount of incorrect information on the subject out on the ‘net too. So, let’s let the maths do the talking. TL;DR – As […]

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The post TCP/IP over VXLAN Bandwidth Overheads appeared first on Packet Pushers Podcast and was written by Steven Iveson.

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Cyber Spring Cleaning! Don’t Forget Your Wireless Router!

As the weather warms up articles to remind us about cleaning up our devices, online accounts, making backups, and changing passwords are sure to show up, but don’t forget to add your wireless router to this list. Over time the wireless environment may have changed and the number of devices connecting to the network has increased and you have noticed a decrease in the performance. I have listed some items to check to either improve the performance or security of your wireless network.

Upgrade the Router

Electronics age fast and if you’re still running an 802.11g router it is time to upgrade. Look for an 802.11n protocol wireless router or get the latest and greatest 802.11ac router and be ready for the next wave of wireless devices. Either way you’ll notice a performance boost and the router won’t create a bottleneck in the network.

Check for the Latest Firmware

While not as often as Windows or Apple software updates a routers software called firmware does get the occasional update. Firmware could add functionality, patch bugs, or add security features. When you log into the routers management interface look for the firmware section to verify the current version and download Continue reading

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Hey, Remember vTax?

Hey, remember vTax/vRAM? It’s dead and gone, but with 6 Terabyte of RAM servers now available, imagine what could have been (your insanely high licensing costs).

Set the wayback machine to 2011, when VMware introduced vSphere version 5. It had some really great enhancements over version 4, but no one was talking about the new features. Instead, they talked about the new licensing scheme and how much it sucked.

While some defended VMware’s position, most were critical, and my own opinion… let’s just say I’ve likely ensured I’ll never be employed by VMware. Fortunately, VMware came to their senses and realized what a bone-headed, dumbass move that vRAM/vTax was, and repealed the vRAM licensing one year later in 2012. So while I don’t want to beat a dead horse (which, seriously, disturbing idiom), I do think it’s worth looking back for just a moment to see how monumentally stupid that licensing scheme was for customers, and serve as a lesson in the economies of scaling for the x86 platform, and as a reminder about the ramifications of CapEx versus OpEx-oriented licensing.

Why am I thinking about this almost 2 years after they got rid of vRAM/vTax? I’ve been Continue reading

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CCIE: You need to recertify in twelve months

This means two things: I’m CCIE for over one year now I need to prepare again the written exam The last day to test the v4 edition is June 3, 2014, I’ve passed that exam twice so I expect a…

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“Fun” with RFC4620 Section 6.4 and discovering IPv4 information over IPv6

As part of a request at work to figure out IPv4 addresses of devices on a network where broadcast pings don’t work, and no administrative access to the switches/routers, I took a look at solving this with IPv6. We know that you can ping6 the all-nodes multicast address, and get DUP! replies from IPv6 enabled hosts on that LAN segment. These will typically be link-local addresses, from which you can determine a MAC address. How to resolve that MAC address on a client host and not the router/switch, I was thinking reverse ARP or something, but support for that wasn’t present in my Ubuntu 13.10 kernel on the main machine I was working with. I started looking around for other options using IPv6 and found RFC4620, Section 6.4.

The gist of it is that you send an ICMPv6 Type 139 packet to an IPv6 address, asking if it has any IPv4 addresses configured either on that interface the target address is on, or any interfaces on the machine itself. And this is why this is disabled by default on hosts, and *IF* you insist on filtering ICMP6 Types, definitely make certain this is one of them. It works Continue reading