Managing access lists is one of the more painful parts of being a network engineer. Once you've finishing working out what should or should not be allowed, you write the ACL and then paste it into all your devices. The minute you finish, the requirements change or the business lets you know what you just broke. In the future, SGTs and SDN promise to fix this problem, but you might not be there yet. `mod_acl` is a simple and fast way to manage ACLs.
Small data gathering utilities are one of my favorite forms of automation. They provide immediate value and have no risk of failure. Netwatch runs a set of commands periodically against a group of network devices. It features concurrency, error handling and just the right amount of customization. Netwatch was inspired by a post on Reddit and the *nix utility watch.
Interacting with Network Devices can often be I/O limited. A function runs, waits for a response from the device, then another function runs so on and so forth. This is made worse by the fact that scripts are often run against multiple devices. After all the purpose of scripting is to speed up repetitive tasks.
By Brandon James on 2019-02-17 Tags: Automation
In the past when I was using TCL/Expect as my primary automation language, I would do most of my configuration within the script itself and then I'd just have the script grab a list of devices from a text document. Lately, I've been using YAML to provide both my list of devices and to configure various parameters within the script itself.