Installing an operating system remotely comes handy when you don’t want to spend all the time required for the install process next to the physical machine or want to give someone else access to perform the procedure.
CentOS is one of the OSes which supports remote installation using the VNC protocol.
By default SSHd will terminate an ongoing connection if there was no traffic (incoming or outgoing) for a while.
If you usually leave remote sessions running for long amounts of time and hate the unexpected disconnects, this can be changed by enabling the keep-alive feature on the server directly so it applies to all remote sessions regardless of client used.
CentOS is a conservative distribution giving you the most stability and security, at the expense of newer features like the latest PHP release.
Fortunately there are ways around for getting a newer PHP by using one of the several repositories out there providing updated packages. My personal choice for this task is Remi’s Repository.
Since OPNsense is more vanilla FreeBSD it is a lot simpler to install additional FreeBSD software on it than on pfSense.
One piece of additional software that can be useful, especially for monitoring and statistics purposes, is munin.
I have been looking for a good alternative which could handle my gigabit internet connection and I believe I made a good choice going with PCEngine’s APU2 embedded system.
I tried following various tutorials dedicated for installing both pfSense and OPNsense on this device, however they didn’t quite work on the APU (or in my case), so I tried a personal method which proved successful.
Webmin is not part of the OPNSense repository packages, however as OPNSense is more vanilla FreeBSD than pfSense it is relatively easy to install additional packages.
For compatibility and stability reasons the FreeBSD repository is disabled by default, but it can be enabled…
When assigning multiple IP addresses to a single server by using virtual interfaces on the same single main interface it is necessary to switch to a static IP configuration.
Doing network configuration remotely is a bit risky but with the correct sequence of steps it is possible to switch from DHCP to static IP without any downtime.
For security and efficiency reasons, a hosting system DNS server should not answer recursive queries (solve DNS requests for domains it is not authoritative for).
However, the DNS server needs to accept recursive queries for the services hosted on the same system for these services to work correctly and be able to resolve forward and reverse hosts/IPs.
In some instances using the ISP’s DNS service is not desirable. Maybe for speed or maybe for privacy concerns a trusted DNS provider is preferred instead.
While the DNS settings can be manually changed after each (re)connection, applying a permanent solution requires a bit of file fiddling.
Data always piles up and on a small VPS the storage space can quickly get consumed by leftover or unused programs.
When things get too crammed it’s time to use the available tools and clean up some of the unwanted things.
Linux generally keeps multiple versions of the kernel installed. This is done to maintain backwards stability and allow the selection of an older (tried and tested) kernel if the latest update fails in any way.
On a small system all these kernel versions can quickly add up and waste valuable space. In such case keeping only the needed versions (the latest and the one currently booted, if different) is an acceptable risk to take.
You’ll need a fairly recent operating system distro (CentOS is too conservative and failed for me, but Ubuntu 16.04 LTS worked fine) and a couple of programs and packages.
