DHCP server on a /32 subnet

How to force a DHCP server to hand over /32s, while running on a different /32 subnet.

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ECMP problems between two systems

Solving a tricky problem with ECMP between two machines, where one system refused to balance connections at random intervals.

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Looking Glass Collection

A collection of looking glasses of various ISPs

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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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SSH jumping through multiple jump hosts

The standard OpenSSH SSH client accepts the argument -J to allow users to utilize a jump host/jump box.

What I recently discovered (and isn’t immediately obvious from the documentation) is that you can actually specify multiple jump hosts – separated by a comma – and the SSH client will jump through each single one in order to reach the target.

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dig TXT whoami.ds.akahelp.net.

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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