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.
Category: Linux
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.
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.
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. Continue reading
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.
Backing up OVH Public Cloud instances using snapshots
OVH Public Cloud platform is based on OpenStack software. As such, it has an API using which many procedures can be automated. Today I will be showing how to automatically create whole server backups using snapshots.
Postfix: Routing outgoing email based on sender domain
I was in a situation where I needed to implement a mail routing policy: Outgoing email from a specific domain gets routed through a relay (eg. Amazon SES) and all other goes directly.
Compiling nginx with PageSpeed and naxsi
Today we are going to compile nginx web server with naxsi WAF (Web Application Firewall), Google PageSpeed modules and HTTP/2 support.
Nginx reverse proxy with code injection
Using nginx as a reverse proxy is very easy to do and there are many guides on the internet on this topic. However there’s not a lot of content regarding modifying proxied data on-the-fly. Here’s how to do it
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.
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.
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. Continue reading
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.
Backing up OVH Public Cloud instances using snapshots
OVH Public Cloud platform is based on OpenStack software. As such, it has an API using which many procedures can be automated. Today I will be showing how to automatically create whole server backups using snapshots.
Postfix: Routing outgoing email based on sender domain
I was in a situation where I needed to implement a mail routing policy: Outgoing email from a specific domain gets routed through a relay (eg. Amazon SES) and all other goes directly.
Compiling nginx with PageSpeed and naxsi
Today we are going to compile nginx web server with naxsi WAF (Web Application Firewall), Google PageSpeed modules and HTTP/2 support.
Nginx reverse proxy with code injection
Using nginx as a reverse proxy is very easy to do and there are many guides on the internet on this topic. However there’s not a lot of content regarding modifying proxied data on-the-fly. Here’s how to do it