Category: Networking

Retaking control of your network: Part 2

Computer networks are becoming increasingly complex with more and more devices connected each day. Gaining network visibility is absolutely crucial to ensure your traffic flows smoothly and transit costs are kept low. In this mini-series I will show you how to set-up sFlow sampling on Linux, aggregate the data and finally present it in flashy graphs.

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Retaking control of your network: Part 1

Computer networks are becoming increasingly complex with more and more devices connected each day. Gaining network visibility is absolutely crucial to ensure your traffic flows smoothly and transit costs are kept low. In this mini-series I will show you how to set-up sFlow sampling on Linux, aggregate the data and finally present it in flashy graphs.

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Core Backbone/AS33891 BGP Action Communities

A list of available action BGP communities for Core Backbone, AS33891.

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Vultr List of Transits

I compiled a list of Vultr transits per location into a spreadsheet

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OVH test IPs

Recently I found a list of test IPs for various OVH locations.

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“Why is my internet down?” | Analysis of a BGP leak causing a global outage

Explanation and analysis of today’s internet outage. What happened and what could’ve been done to prevent this?

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Fun with .arpa domains

As you may know, .arpa domains are used for reverse DNS. But did you know that they are usable for forward DNS too?

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ECMP on Linux

During a new server deployment I’ve come across the need to use ECMP on Linux. Turns out it’s actually really simple to configure. Read more →

Bird Unreachable Routes on multihop BGP Sessions

In the past few months, quite a few people have asked me this question: “I bought a VPS from provider X, turned up a BGP session with them and my routes are all marked unreachable”. Today’s post will hopefully shed some light on what causes this phenomenon and how to deal with it.

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Configuring Tunnel Broker BGP on Mikrotik

Hurricane Electric’s free service Tunnel Broker allows one to set-up 6to4 tunnels in order to get IPv6 connectivity to IPv4-only sites. In addition to “regular” tunnels, where they assign you a random prefix from their ranges, they also support BGP┬átunnels. Today I will show you how to set one up and configure it on a Mikrotik device.

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