It's Never The Network

It's Never The Network
A place to plan, troubleshoot and learn about computer networks and other cutting edge infrastructure technologies.

Tools

This list is constantly growing, so be sure to check back.

cURL - Send a HEAD request from the NTN Webserver

DNS - Send DNS queries from the NTN Webserver

Ping - Ping servers from the NTN Webserver

Subnet Calculator - Calculate IPv4 and IPv6 Subnets

Traceroute - Run traceroute from the NTN Webserver

OUI Lookup - Find device manufacturers based on MAC Address

Whois - Find the owner of an IP address or Domain

RP Hash - Calculate PIM RP Hash Values

Latest Articles

Practical Automation - mod_acl

By Brandon James on 2019-12-31 Filed Under: Route/Switch, Automation, Programming
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.

Bootstrap Router Hash Function

By Brandon James on 2019-12-06 Filed Under: Route/Switch, Programming
RFC 7761 describes a hash function used to load balance multicast groups between Rendezvous Point (RP) candidates when you are using Bootstrap Router (BSR). The hash function isn't straight forward and I was unable to find a resource that described it in detail. One feature of the hash function is an adjustable hash mask length. I think it's important to understand what the function does and how adjusting the mask impacts RP selection. I do my best to describe it here and provide some resources to help you select the best hash mask length for your environment.

Never The Network

By Brandon James on 2019-11-23 Filed Under: unfiled
A month ago I decided to submit NTN to Cisco's IT Blog Awards in the Best Newcomer Category. To my surprise it got selected as a finalist. Since I don't have an about page, I wanted to briefly write about who I am, what NTN is and my plans for the future of NTN.

A Power User's Guide to the Linux CLI

By Brandon James on 2019-10-10 Filed Under: Cheatsheets, Linux
At first, I was using Linux because I'm a nerd and that's what we do, but I continue to use it because it increase my productivity.