John W Kerns
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John W Kerns
CDP and LLDP Neighbor Parser – neighborparser.com
As a network engineer, I’ve made heavy use of the [crayon-6458f26173405144816985-i/] and [crayon-6458f2617340b267906839-i/] commands to discover the physical topology of a network without having to physically trace cables. While these are very useful commands, their output is not very human-readable. I built neighborparser.com as a quick-and-easy tool to turn the semi-structured data from these commands […]
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MacOS Ventura 13.1 Breaks Wireshark
If you recently updated your Mac to Ventura 13.1 or 13.2, and you had installed Wireshark previously, then you may be having some trouble. If you open Wireshark, you will likey see the message “You don’t have permission to capture on local interfaces” and “You can fix this by installing ChmodBPF“. Even after installing this […]
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Linux Bonding, LLDP, and MAC Flapping
Sometimes a painfully troublesome networking problem can have a complicated and brain-twisting root cause, one which you dread having to explain to peers and managers. However, sometimes the root cause is dead simple and makes you feel silly for how long it took you to find it. Today, I had one of the latter and […]
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Proxmox/Ceph – Full Mesh HCI Cluster w/ Dynamic Routing
If you have ever used Proxmox, you know it’s a capable and robust open-source hypervisor. When coupled with Ceph, the two can provide a powerful HyperConverged (HCI) platform; rivaling mainstream closed-source solutions like those from Dell, Nutanix, VMWare, etc., and all based on free (paid support available) and open-source software. The distributed nature of HCI […]
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Ubuntu: Extend your default LVM space
POV: You’re a sysadmin who set up a one-off Linux machine for an app you needed, and now it’s out of disk space. You originally spun up a VM, installed a recent Ubuntu OS, and just hit Next, Next, Finish through the guided install. Linux is not your bread-and-butter, you usually deal in Windows, and […]
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Meraki-CLI – Command Line Utility for the Meraki Dashboard
Meraki changed the industry years ago as one of the first platforms to use a cloud portal for all configuration; forgoing the typical local CLI/GUI administration of network appliances. One of the first things a traditional network engineer (like myself) may notice about Meraki equipment is their complete lack of a command-line interface. For the […]
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FreeZTP: Zero-Touch Provisioning for Cisco Catalyst
Configuring Cisco IOS switches the “old-fashioned” way can be a time consuming and tedious task. Pull out the serial cable and USB adapter, connect your laptop to the switch, and sit on the cold raised floor banging away at the keyboard until you have remote access and can escape to a more terran-friendly environment. There […]Network Documentation Series: Logical Diagram
In this article, I will do a walk-through of a logical network diagram. As I also said in the Physical Diagram article: I prefer to use the term “logical” instead of “L3″ because it is more easily understood by somebody unfamiliar with the OSI model. It also removes the assumption (made by many non-technical people) […]
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The post Network Documentation Series: Logical Diagram appeared first on Packet Pushers Podcast and was written by John W Kerns.
Network Documentation Series: Physical Diagram
Introduction to the Physical Diagram This article is a quick tutorial for creating and maintaining a physical network diagram. I prefer to use the term “physical” instead of “L1″ because it is more easily understood by somebody unfamiliar with the OSI model. It also removes the assumption (made by many non-technical people) that “L1″ and […]
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The post Network Documentation Series: Physical Diagram appeared first on Packet Pushers Podcast and was written by John W Kerns.
Network Documentation Series: Preamble
This post is the first in a series of articles tackling the topic of creating and maintaining proper network documentation. Each article will include a file which can be downloaded and used as a template for creating the document covered. Below you will find a few generic documentation best practices which apply to all documents […]
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The post Network Documentation Series: Preamble appeared first on Packet Pushers Podcast and was written by John W Kerns.
Cisco NAT Cheat Sheet
I’ve always had a difficult time when attempting to remember how to implement the different types of NAT available on ASA and IOS devices. It doesn’t help that between the two device families, there are three different syntax versions used in the configurations. I created the PDF linked below as a quick reference sheet. It […]
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The post Cisco NAT Cheat Sheet appeared first on Packet Pushers Podcast and was written by John W Kerns.