Recently I wanted to look at the structure of sFlow packets. Of course I can read the specs, but it’s often easier to look at some real packets. So I set up a simple network, configured sFlow, created some traffic across the network, and used tcpdump to capture the sFlow packets.
Unfortunately I had a bit of a brain fade, and configured sFlow to use port 2055, not port 6343. So it looked like this:
vagrant@ubuntu:~$ tcpdump -r sflow.cap reading from file sflow.cap, link-type EN10MB (Ethernet) 13:48:37.812602 IP 10.254.4.125.44695 > 10.254.4.170.2055: UDP, length 148 13:48:57.813663 IP 10.254.4.125.44695 > 10.254.4.170.2055: UDP, length 148 13:48:59.061629 IP 10.254.4.125.44695 > 10.254.4.170.2055: UDP, length 232 13:49:17.806908 IP 10.254.4.125.44695 > 10.254.4.170.2055: UDP, length 148 13:49:37.804433 IP 10.254.4.125.44695 > 10.254.4.170.2055: UDP, length 148 13:49:57.806000 IP 10.254.4.125.44695 > 10.254.4.170.2055: UDP, length 148 13:50:17.808959 IP 10.254.4.125.44695 > 10.254.4.170.2055: UDP, Continue reading
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A hole in OpenSSH roaming has been out there since 2010.
Jinja2 is a templating language that was originally used as part of the Flask python web framework. From the Jinja2 website
Jinja2 is a full featured template engine for Python. It has full unicode support, an optional integrated sandboxed execution environment, widely used and BSD licensed
It was originally developed to help automatically generate HTML dynamically as part of the flask framework, more on that in another post, but it can also easily be used to help us generate our configuration files for our infrastructure devices.
This is going to be a very simple introduction to a few of the basic concepts of that jinja uses which, hopefully, will help to understand how Jinja can be used as a first step down the road of gaining automation skills.
We’ll take a look at a developing some intuition on how Jinja2 can be used to create basic network infrastructure device configurations. This is definitly not the modern method of interfacing directly into the control/data/management plane of devices using APIs, but it’s definitely a step in the right direction on understanding how a bit of code can help make your life better.
I’m assuming you’ve already Continue reading
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On this episode of "The Next Level" we walk through 6 steps to help you design and assemble a technical team, set clear expectations, and manage this team for long-term success.
The post Community Podcast: The Next Level – Building A Technical Team appeared first on Packet Pushers.
On this episode of "The Next Level" we walk through 6 steps to help you design and assemble a technical team, set clear expectations, and manage this team for long-term success.
The post Community Podcast: The Next Level – Building A Technical Team appeared first on Packet Pushers.

The post Worth Reading: Optical Processing appeared first on 'net work.
Intel's Ravi Varanasi tackles best practices for securing the software-defined data center.