Tech blog

This blog is intended as a tech blog targetting other network admins as well as some home automation projects. All information and tutorials are provided as-is and there is no guarantee this will work exactly the same in your environment. All posts are my own and do solely reflect my own opinion and not that of my employer.

SDWAN - Webhook Problem w/ a Certificate Error

Today a short post regarding webhooks on vManage. The actual setup is already described by Cisco and Suchandan Reddy (Technical Marketing Engineer - Cisco SD-WAN). I will mention that the setup of an e-mail server and address is no longer neccessary in versions > 20.3, however, the webhook server’s username and password should be filled in. I usually set it to ‘dummy’/‘dummy’ as most webservers will ignore this data if not required. [Read More]

SDWAN - Repair a vBond Sync Error

Another short entry to help those out who might run into a similar situation as I did this week. In the SD-WAN fabric, every once in a while the controller certificates need to be updated so that the cEdges and vEdges, but also the controllers themselves can authenticate one another. This week, I reconfigured the vManage to use the Cisco Automated using this CVD from Cisco. The process is relatively straight forward, but it’s important to update the cEdges and vEdges with a new root certificate so that they will successfully authenticate with the new Cisco issues certificates. [Read More]

SDWAN - LTE fail-over not working with TLOC extensions

A short entry today regarding the set up of LTE in Cisco SD-WAN with respect to the ISR1111 routers. For a client, I’m prepping a set of routers and for most branch locations, the ISPs provide an IP over DHCP on their WAN. Similarly, in our case most LTE carriers provide a dynamic IP as well. LTE is, be default, only useable as a fall-back solution. Because of how it functions, it will not work as expected when using a branch routers with a TLOC extension. [Read More]

Setting up a new Windows Dev environment with WSL 2 & VS Code

Today I had the pleasure of getting a fresh new Windows image on my work laptop. Mind you, I still prefer a MacOS or Linux distro, but you can’t have it all. Setting up WSL in Windows is I guess the next best thing. This post provides a guide on how-to setup WSL and integrate it into VS Code for development purposes. What is WSL For those that are not familiar with WSL, this is the Windows Subsystem Linux. [Read More]

Nexus 9k VPC (back to back) and FHRP setup in 2 data centers

This post describes the setup of VPCs on a data center interconnect and HSRP as the first hop redundancy protocol for the VLAN interfaces (SVIs). This configuration has been performed on a Nexus 93180YC-EX with software version 7.0(3)I7(8). The switches have the system default switchport command set, so all ports are switchports by default, but this does not matter for the setup. Background This configuration is for a setup where the current network “core” is a Catalyst 6500 in VSS mode with a chassis in each data center. [Read More]
Cisco  Nexus  VPC  FHRP  HSRP 

Cisco vEdge Cloud Certificate Installation

Like some of the other articles I’ve written, this serves mostly as a documentation page to myself. The last time I had to manually install a certificate on a vEdge cloud router was six months ago, so it’s something you easily forget. This guide was written for vEdge Cloud 18.3.3. Installing a vEdge Cloud router It’s fairly easy to install the vEdge Cloud router. There are images available for VMs in all the major clouds. [Read More]

Network Automation Tools

Network automation was THE network topic of 2019, and perhaps for 2020 as well, although COVID-19 is a strong candidate as well. However, network automation not a new idea or technology. It’s becoming more prevalent in our networks through vendors (finally) adding more API support, but also products such as Cisco DNA Center, various SD-WAN products and so on; Networks with controllers that provide a programmatic interface. In the age of DevOps, everything needs an API and networking vendors are finally coming around to supporting it. [Read More]

VSCode for network engineers

I would like to share with you my favorite tool for my work available on Windows. Why favorite? Well, Linux and MacOS have all the other tools (iterm2 anyone?) that are not available on Windows so the competition is not that amazing. Apart from that, it must be said that VS Code is an absolute killer-app. A swiss army knife if you will of text editing, coding and syntax highlighting. I use this tool for almost anything except e-mail. [Read More]
Code  Tools 

Solarwinds queries repo

Today I would like to quickly point out that I’ve started to ‘open source’ some of my Solarwinds queries. I’ve noticed a lot of people on the web struggling with getting more out of this product. I’ve added a new (public) repo under my github profile that might help fellow network admins get a bit more useful info out of their Solarwinds instances. Solarwinds is a nice tool, but it’s definitely missing some very basic info regarding network devices. [Read More]

Solarwinds - Monitoring DMVPN

Again, this week a request for Solarwinds reporting utilizing some SQL knowledge on my part. The idea was to create a report on DMVPN connections. The build-in web reporter does a fairly decent job creating this report already. However, the IP addresses in this report do not reflect the actual interface addresses (or perhaps it’s an user issue ;) ). Query Solarwinds Start by opening and connecting to the Solarwinds database in SWQL Studio. [Read More]