Load Balancing Exchange 2016 behind HAProxy

I recently started the upgrade to Exchange 2016 at work. A huge benefit over Exchange 2010, is that REST based client connections are truly stateless. In effect this means that if a server goes down, clients shouldn’t really notice any issues as long as something redirects them to a working server. In my system, this… Continue reading Load Balancing Exchange 2016 behind HAProxy

iOS 11 drops 32-bit app support – do we care?

In the upcoming months and until a short while after Apple’s inevitable autumn event where they’ll publicly release their new operating systems, computer magazines and news sites will try to create headlines about how Apple is killing off tens or hundreds of thousands of apps. What’s true and what’s not about this? Well, yes: iOS… Continue reading iOS 11 drops 32-bit app support – do we care?

SFTP revelations

I got myself into a situation where I had to copy some files from my computer to a server that presented sftp but not scp. Since I’ve never needed to use the sftp protocol from a cli-only machine, I haven’t really thought about how it works in non-interactive mode. Batch mode allows you to create… Continue reading SFTP revelations

WordPress behind HAProxy with TLS termination

My current project has been to set up a publicly accessible web server with a decent level of security. It has been an interesting exercise in applying “old” knowledge and gathering some new. This weekend I finished this project for now. The current setup is as follows: Behind my firewall, where I NAT port 80 and… Continue reading WordPress behind HAProxy with TLS termination

The paravirtual SCSI controller and the blue screen of death

For driver reasons, the default disk controller in VMware guests is an emulated LSI card. However, once you install VMware Tools in Windows (and immediately after installing the OS in most modern Linux distributions), it’s possible to slightly lower the overhead for disk operations by switching to the paravirtual SCSI controller (“pvscsi”). I’m all for lower… Continue reading The paravirtual SCSI controller and the blue screen of death

Securing an Internet accessible server – Part 2

In part 1 we made it significantly harder to gain access to our server once it is opened up to the Internet – but we’re not quite ready for that yet. In this post we’re exploring a firewall in Ubuntu, ufw, which stands for “uncomplicated firewall”, and we’ll set up some additional hardening using Fail2Ban to protect ourselves… Continue reading Securing an Internet accessible server – Part 2