Introduction We’re in one of the most exciting times in data networking. While I’m sure we’re all sick of vendors co-opting technologies in their infancy, there is a lot of good work going on to change the fundamentals of moving data (I shudder to call this a paradigm shift; I’ll save that term for life […]
As an avid reader of RFCs and RFC drafts, I’m always running across little bits of knowledge I either already knew and forgot (I forget a lot of things), or things I didn’t know and wouldn’t have expected. RFC5942, published way back in 2010 (a long time in network engineering terms), discusses a topic I […]
This sponsored blog post was written by Clark Zoeller, CCIE #13760, Sales Engineer with ActionPacked Networks. Quality of Service (QoS) is a suite of technologies used to manage bandwidth usage as data crosses computer networks. Its most common use is for protection of real-time and high priority data applications. QoS technologies, or tools, each have […]
The post How Does QoS Work? appeared first on Packet Pushers Podcast and was written by Sponsored Blog Posts.
We’re currently trying to allow a client to perform an operation using SNMP set commands on a Cisco NX-OS switch (namely a 5548).
It’s possible using SNMPv2c and community strings, but this does not generate a log message, making it completely unaccountable. SNMPv3 seems to have the answer. According to the documentation, it provides:
I’ve tested using a set operation to change a MIB using the following command:
snmpset -v 3 -u test -l authpriv -a MD5 -A Testpass01 -x DES -X Testpass01 hostname system.sysLocation.0 s TESTLOCATION
Which works fine.
However, the problem arises when trying to back off the authentication of the SNMP operation to TACACS/RADIUS. My interpretation of the documentation suggests this is possible. My Cisco SE has not denied it either. However, I reckon some changes need to be made to the authentication server. According to what I’ve read:
You can use the VSA cisco-av-pair on AAA servers to specify user role mapping for the Nexus 5000 Series switch using this format:
shell:roles="roleA roleB ..."
If you do not specify the role option in the cisco-av-pair attribute, the default user role is network-operator.
You can also specify your SNMPv3 authentication and privacy Continue reading
Clock and data recovery is an essential physical-layer function of modern switch and router hardware. Digging deep into the electronics of a router may not be your thing, but clock recovery is a fundamental building block for other network hardware … Continue reading
The post Hardware – Clock and Data Recovery appeared first on The Network Sherpa.
I was preparing a presentation the other day about the high level differences between IOS, IOS-XE and NX-OS and one of the things I included in the presentation was the various platform and branch identifiers that’s used in each OS. It’s just a bit of trivia that I thought would be interesting and might come in handy one day. I’m posting the information I collected below so everyone can reference it.
For IOS, you can see the platform identifier in the filename and the “show version” output. If we take an example version string, 15.1(2)SG2, and break it down, here’s what each digit in the string signifies:
15 | .1 | (2) | SG | 2 |
Major release number | Minor release number | New feature release number | Branch/train/platform identifier | Maintenance rebuild number |
The branch/platform identifier can also be seen in the IOS filename:
cat4500e-entservicesk9-mz.151-2.SG2.bin
Here’s a summary of the branch identifiers in IOS 15:
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 […]
The post Show 171 – Cisco FabricPath Deep Dive Part 2 appeared first on Packet Pushers Podcast and was written by Ethan Banks.
I was preparing a presentation the other day about the high level differences between IOS, IOS-XE and NX-OS and one of the things I included in the presentation was the various platform and branch identifiers that's used in each OS. It's just a bit of trivia that I thought would be interesting and might come in handy one day. I'm posting the information I collected below so everyone can reference it.
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
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!
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…
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…
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!