Installing Pyenv on Mac OSX

When I’m writing code, I’m usually in OSX. When I want to try things out, or check for compatibility between certain versions of Python, it’s handy to have them all accessible… enter Pyenv. Pyenv is based on Rbenv, which for you non-Rubyists is a tools that allows you to set up Ruby environments that are scoped either globally, per-shell or per-folder!

If you aren’t using Homebrew already, which I highly recommend you should, then install it.

ruby -e "$(curl -fsSL https://raw.github.com/mxcl/homebrew/go/install)"

Before you start brewing you should run “brew doctor”. This will check that everything is ok with your installation.

brew doctor

Hopefully you will get a message “Your system is ready to brew”, otherwise doctor brew will oftentimes tell you what to do.

brew install python
brew install pyenv

The above commands will, install homebrew’s Python 2.7 (to replace the system pyhton) and install pyenv. Replacing the system Pyhton fixes issues with needing “sudo” for easy_install and others documented here

Now Pyenv is installed, you should edit your “~/.bash_profile” and add the following:

export PYENV_ROOT=/usr/local/opt/pyenv  
eval "$(pyenv init -)"

This changes the Pyenv root path and makes sure pyenv is initialized.

$SHELL -l

Bypassing the memory check on a VMware ESXi 5

When my new HP ML10 arrived I was ready to install ESXi… until I realised that my 32GB of RAM wouldn’t be on its way for a week! To get around the memory check in ESXi 5.5, I found the awesome instructions here and with a few tweaks was able to get this working. Here are the 20 steps that I followed…

Bypassing the memory check on a VMware ESXi 5

Boot the system from USB Stick with ESXi installer on it.
Once the installer welcome screen shows up, press ALT+F1
Login as “root”, no password.
cd /usr/lib/vmware/weasel/util
Delete upgrade_precheck .pyc (compiled version)
Move precheck.py to precheck.py.old
cp upgrade_precheck.py.old upgrade_precheck.py
chmod 666 upgrade_precheck.py
vi upgrade_precheck.py
Type “/MEM_MIN” and press ENTER
Press “i” for insert
Edit the line to read “MEM_MIN_SIZE= (1*1024–32)”
Press ESC and then type “:w” and ENTER
Press ESC and then type “:q!” and ENTER
ps -c | grep weasel
Note the process id for “python”
kill –9 /<process_id/>
This put me back at the main screen, but you can jump back pressing ALT+F2 if necessary
Continue the install process
Fin

Bypassing the memory check on a VMware ESXi 5

Installing Pyenv on Mac OSX

Install Open vSwitch v2.0 from RPM on RedHat Fedora

This post is for installing OVS from RedHat RPM binaries. If you want to build Open vSwitch from source please see this post. Open vSwitch v2.0 introduces some really important features, at the top of the list is multi-threaded support in vswitchd. This will increase flow instantiation rates significantly into the upstream kernel module. A rough guess would be from ...

...

About Promotion

There is no such thing as career path.

I wrote this several years ago. And I believe it's still true. For those who don't understand why I wrote such thing, please spend few minutes to read that blog post before leaving nasty comment. (This means: you still can leave nasty comment after reading that post :))

Allow me to share my secret: patience is not my virtue.

Every time I want to change to new position, or to new job title, I move to new company. Some of my previous employers offered me promotion the moment I gave them my resignation letter. Some of them simply didn't care and just let me go. For those who offered me promotion, I never accepted the offer. I thought they should have offered that while I was still with them, not at my last moment in the company when I usually had decided to leave.

There was a time I even worked as independent contractor. Had to deal with the customer directly, defined the scope by myself, set the performance index, and delivered end-to-end solution to customer. No job title. No career. Hmm, good old days. Even it was only for several months Continue reading

Hadoop for network engineers part 2 – adding more nodes

In the first article here, I walked through importing netflow data into a single Hadoop instance (pseudonode) and mentioned a progression of the project to add multiple nodes. The ability to do distributed storage and distributed processing of data is ultimately the benefit of using Hadoop/HDFS. So, let’s expand on the project and add one or […]

Author information

JR Mayberry

I build large networks. I secure large networks. Seattle based. Formerly Comcast, TorreyPoint, Coca-Cola and current Microsoft. Philly born and raised. Personal website: http://www.rickmayberry.com twitter: mayberry0404 linkedin: http://www.linkedin.com/in/mayberry0404

The post Hadoop for network engineers part 2 – adding more nodes appeared first on Packet Pushers Podcast and was written by JR Mayberry.

Show 170 – The Spanning Tree Story and More SDN Analysis

This week it’s Greg was configuring spanning tree in the data centre and had a problem with a switch cluster that didn’t work proper. How much networking do you need in a data centre ? Lets say you purchases 2 x 32 port 40GbE switches (common Trident2 configuration) for USD$30K and you use QSFP breakouts […]

Author information

Greg Ferro

Greg Ferro is a Network Engineer/Architect, mostly focussed on Data Centre, Security Infrastructure, and recently Virtualization. He has over 20 years in IT, in wide range of employers working as a freelance consultant including Finance, Service Providers and Online Companies. He is CCIE#6920 and has a few ideas about the world, but not enough to really count.

He is a host on the Packet Pushers Podcast, blogger at EtherealMind.com and on Twitter @etherealmind and Google Plus.

The post Show 170 – The Spanning Tree Story and More SDN Analysis appeared first on Packet Pushers Podcast and was written by Greg Ferro.

Troubleshooting EIGRP Neighbor Relationships

How does the internet work - We know what is networking

EIGRP internals and getting hands dirty in debugging routing adjacency and solving EIGRP neighboring issues. What is sequence TLV and Conditional Receive CR-mode and CR flag Couple of days ago I got a strange network behavior in my CCIE lab. Something was wrong between a router and L3 switch connection and there was EIGRP neighbor […]

Troubleshooting EIGRP Neighbor Relationships

Five Functional Facts about VXLAN

It seems appropriate to write a FFF post about Virtual Extensible LAN (VXLAN) now since VXLAN is the new hotness in the data center these days. With VMware’s NSX using VLXAN (among other overlays) as a core part of its overall solution and the recent announcement of Cisco’s Application Centric Infrastructure (ACI) and the accompanying Nexus 9000 switch, both of which leverage VXLAN for delivering a network fabric, it seems inevitable that network engineers will have to use and understand VXLAN in the not too distant future.

As usual, this post is not meant to be an introduction to the technology; I assume you have at least a passing familiarity with VXLAN. Instead, I will jump right into 5 operational/technical/functional aspects of the protocol.

For more information on VXLAN, check out the draft at the IETF.

1 – VXLAN Use Cases

Despite the apparent ubiquity and fervent hype around VXLAN, it’s actually been designed to solve specific problems. It has not been designed to be “everything to everyone”.

vxlan_all_the_things

The first, and most often cited, use case is for data center operators that require more than ~4000 logical partitions in the network. These 4000 partitions equate to the maximum number of Continue reading

Five Functional Facts about VXLAN

It seems appropriate to write a FFF post about Virtual Extensible LAN (VXLAN) now since VXLAN is the new hotness in the data center these days. With VMware's NSX using VLXAN (among other overlays) as a core part of its overall solution and the recent announcement of Cisco's Application Centric Infrastructure (ACI) and the accompanying Nexus 9000 switch, both of which leverage VXLAN for delivering a network fabric, it seems inevitable that network engineers will have to use and understand VXLAN in the not too distant future.

For more information on VXLAN, check out the draft at the IETF.

New GNS3 – Redesign changing networking again

GNS3 has been a crucial tool used by many network engineers to emulate computer networks. It has proven to be fundamental studying for all network certification levels such as CCNA, CCNP and CCIE. It has been crucial for network design validations within many companies. With the news of Cisco’s VIRL, many said that GNS3 will disappear, but that doesn’t seem to be the case. GNS3 is going through a major redesign and needs the help of all the engineers that it helped over the years.

Recently, Stephen Guppy from GNS3.net contacted me about some of the changes coming to GNS3. He was very excited to share with me the new direction they are heading and the croudfounding campaign going on. These new software improvements incorporate:

Switching
On Demand Cloud Processing
Automation of Configuration
Lab Deployment and Training Programs
Integration of Other Vendors

Switching

Switching has been a major feature preventing network engineer from exclusively using GNS3 for their certification study. The difficulty in supporting switching platforms is that most of their ASCIs were build on proprietary hardware and can’t be easily ported. With the new GNS3, switching will be supported using L2IOU. Some features are not supported Continue reading

How TPM-protected SSH keys work

In my last blog post I described how to set up SSH with TPM-protected keys. This time I'll try to explain how it works.

SRK

The SRK is a public key pair that is the main secret inside the TPM chip. It is always generated by the chip, and the private key cannot be read or migrated.

In order to use the SRK key with any operation, the SRK password must be supplied. The SRK password is just an access password. It's not related to the key itself. The SRK password is usually set to the Well Known Secret (20 null characters), or sometimes the empty string, or something silly like "12345678".

There is not much point in having a good SRK password, since you probably have to store it on disk somewhere anyway, to allow TPM operations by daemons.

If you want a password then you probably want to set that per key, not chip-wide like the SRK password is.

Key generation

The stpm-keygen binary asks the TPM to generate a key, and the TPM hands back the public portion of the key, and a "blob" that has no meaning to anyone except the TPM. The blob is encrypted Continue reading

How TPM-protected SSH keys work

In my last blog post I described how to set up SSH with TPM-protected keys. This time I'll try to explain how it works.

SRK

The SRK is a public key pair that is the main secret inside the TPM chip. It is always generated by the chip, and the private key cannot be read or migrated.

There is not much point in having a good SRK password, since you probably have to store it on disk somewhere anyway, to allow TPM operations by daemons.

If you want a password then you probably want to set that per key, not chip-wide like the SRK password is.

Key generation

On Python, Networks and the py-junos-eznc library

One of my recent forays into Increasing the Awesome has involved learning about NETCONF and the Python programming language. I was lucky enough to spend some time with Jeremy Schulman during my trip to Sunnyvale for the Juniper Ambassadors Summit, and he introduced me to the new py-junos-eznc Python library he has been working on. I had spent a little bit of time earlier in the year looking at the original Ruby library, and I was amazed at how much thought had been put into this new library – obviously Jeremy’s learned a lot on the way!

An Impatient Start

Let me make a couple of things clear right from the outset:

I am not a programmer! Yes I have written the odd script here and there in the deep dark past, but I am by no means a programmer. All of my scripts have been about automating some task I had to do. As long as it worked, I didn’t care how efficient or pretty it was – it did what I needed.
I have no intention of becoming a full time programmer! I like being a network architect and I like building and playing with Continue reading

Quiz #21 &#8211 EIGRP as CE-PE

You have just received a nice job at a big enterprise that has multiple sites connected over their own managed MPLS Core. Each site runs EIGRP as the CE - PE routing protocol. You get the task to route some traffic in a particular way, but you cannot make it. What is missing ?

A Bit of Irony…

There’s something terribly wrong about this… RUSH hour in Nairobi can be a nightmare. “Most motorists don’t follow traffic rules and small inconveniences like a minor traffic accident or even a sudden downpour can cause delays of up to an hour,” says John Kimani, a small business owner in the Kenyan capital. A text message […]

Author information

Russ White

Principle Engineer at Ericsson

Russ White is a Network Architect who's scribbled a basket of books, penned a plethora of patents, written a raft of RFCs, taught a trencher of classes, and done a lot of other stuff you either already know about, or don't really care about. You want numbers and letters? Okay: CCIE 2635, CCDE 2007:001, CCAr, BSIT, MSIT (Network Design & Architecture, Capella University), MACM (Biblical Literature, Shepherds Theological Seminary). Russ is a Principal Engineer in the IPOS Team at Ericsson, where he works on lots of different stuff, serves on the Routing Area Directorate at the IETF, and is a cochair of the Internet Society Advisory Council. Russ will be speaking in November at the Ericsson Technology Day. he recently published The Art of Network Architecture, is currently working on a new book in the area Continue reading

Your Weak and Broken Heart

I can make you happy, I can give you everything you dreamed of. You already know that right? I’ve tried to make you understand this again and again; I’ll fall at your feet at a moments notice, but somehow I’m always here in the background, a shadow. No matter your heart, somehow I’m always put […]

Author information

Steven Iveson

Steven Iveson, the last of four children of the seventies, was born in London and has never been too far from a shooting, bombing or riot. He's now grateful to live in a small town in East Yorkshire in the north east of England with his wife Sam and their four children.

He's worked in the IT industry for over 15 years in a variety of roles, predominantly in data centre environments. Working with switches and routers pretty much from the start he now also has a thirst for application delivery, SDN, virtualisation and related products and technologies. He's published a number of F5 Networks related books and is a regular contributor at DevCentral.

The post Your Weak and Broken Heart appeared first on Packet Pushers Podcast and was written by Steven Iveson.

ASA-CX – 15 Minutes to Configure ASA-CX in a PoC

Just finished building/validating a ASA-CX PoC script. Ran 27K web sites through it using a script on BT5R3. 15min and I was up and running.

Sceenshot of PRSM and Backtrack5 running the script

In the future I may posts the steps required to get this up and running.

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