‹ Nick Plunkett

Tags / Network Engineering

The next speed step in pluggable optics is here and pricing is reaching tolerable levels. While they still use significantly more power than QSFP optics, the actual unit cost of the pluggables is reaching sub $500/pc levels, which makes them viable in many more use cases. I’ve been researching these in order to get myself more familiar with what is available out there. These are my notes for what I’ve found so far. I’ll probably update these a few times as I learn and try more. 400G FR4 The 400G FR4 is a cost-effective pluggable optic that uses duplex LC SMF connectors and operates at a center wavelength of 1310nm. It has a maximum reach of 2km. Features: Duplex LC SMF connectors 1310nm wavelength 2km maximum reach Cost-effective option - available for around $900 list price Use Cases: Short-reach data center interconnects over single mode fiber 1:1 replacement of existing LR4 connections 400G XDR4 The 400G XDR4 is a pluggable optic that uses MPO-12 connectors, single mode fiber, and operates at a center wavelength of 1310nm.
I was recently chatting with a coworker talking through how we use MPO cables and various optics. It made me realize that I have a lot of “in my head” knowledge about fiber cables and optics from working in the networking space over the past 5 years or so, but I haven’t found a good reference point online to point people to and it would probably be better for that information to live written down somewhere rather than it just being in my head. So here it is - everything that is floating around in my head about MPO cables. I’ve done my best to double check what I’m writing here but it should be mostly accurate. What is MPO? MPO (Multi-Fiber Push On) in common terms refers to both the connector and the cable itself.
I have recently been integrating Peering Manager into my network deployment at my day job in order to help automate our BGP configuration & management. We run Arista switches running as routers across our entire footprint. Peering Manager has NAPALM integration built into it, both for managing and deploying configuration as well as polling device status. However, for Arista devices, this requires the Arista eAPI to be enabled on the router, and it must be running in HTTPS mode. That means you need some sort of security certificate installed. I hadn’t dealt with this before and this wasn’t straightforward. I wasn’t able to find great documentation online for how to do this. Below is my process for generating a self signed key, then using that key to generate a self-signed certificate, then using that certificate to allow HTTPS connections to the router over the management interface for eAPI command and control.
Recently, as a part of network automation at $dayjob, I have been provisioning Salt across our network footprint. One particular problem I’ve run into is that we use a dedicated management VRF on all of our devices. This was an issue because by default, commands ran on bash on the Arista software run in the default VRF, and in that state we can’t communicate with our management IP networks. There just isn’t a route to the management networks on the default routing table. Our Salt server only has a Management VRF IP address, and we did not want to configure a proxy to make the Salt master reachable outside the Management VRF. I had previously had no experience with management VRFs on Linux, and there were no articles that were particularly helpful in helping me to run commands specifically in the management VRF of an Arista switch, within the context of the Bash/Linux shell.
I recently have been working on a home network buildout in my new home. One of the features I was excited to implement was PoE - power over ethernet. My main use case for PoE in my home network was going to be to power small desktop switches and routers near the wall mounted ethernet ports, in order to eliminate unnecessary wall wart style AC to DC power adapters. I purchased a NETGEAR 16-Port Gigabit Ethernet Unmanaged PoE Switch (GS116PP), one of the highest power budget consumer level fanless switches I was able to find on the current market. It has 16 1Gb ports with a total PoE budget of 183W - more than enough for my needs for now and into the future when it will eventually need to be replaced with a 2.
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