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…
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 […]
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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 […]
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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 […]
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”.
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.
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.
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.
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
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 – 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 […]
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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 […]
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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.
Show 169 – Cisco FabricPath Deep Dive Part 1
Cisco FabricPath is a TRILL-based layer 2 forwarding technology that can take the place of spanning-tree. Allowing a fully-meshed layer 2 network to forward traffic across all links, FabricPath helps customers to make the most of their expensive 10GbE and 40GbE interconnects. In this show, Jamie Caesar, Colby Glass, and Ed Diaz discuss real-world FabricPath […]
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The post Show 169 – Cisco FabricPath Deep Dive Part 1 appeared first on Packet Pushers Podcast and was written by Ethan Banks.
TPM chip protecting SSH keys – properly
Not long after getting my TPM chip to protect SSH keys in a recent blog post, it started to become obvious that OpenCryptoKi was not the best solution. It's large, complicated, and, frankly, insecure. I dug in to see if I could fix it, but there was too much I wanted to fix, and too many features I didn't need.
So I wrote my own. It's smaller, simpler, and more secure. This post is about this new solution.
Why not Opencryptoki?
- It generates at least some keys in software. As I've explained earlier, I want to generate the keys in hardware.
- It generates migratable keys. This is hardcoded, and some people obviously want migratable keys (for backup purposes). So a fix would have to involve supporting both.
- Opencryptoki has no way to send such parameters from the command line key generator to the PKCS11 library. So not only would I have to implement the setting, but the whole settings subsystem.
- The code is big, because it supports a lot of features. Features I don't need or want. They get in the way of me as a user, and of me fixing the other issues.
- The code is of Continue reading
Installing OpenStack ML2 Neutron Plugin with DevStack on Fedora
OpenStack networking is tricky. This is primarily because programmable distributed systems are relatively new beyond the rigid L2/L3 control protocols we have used for the past 20 years. What I am consistently impressed with about OpenStack networking is the innovative network services that systems programmers are developing using APIs and virtual switching. Of course most vendors have a plugin for ......
