Faking a routed subnet with OVH / SoYouStart

I am currently in the process of decommissioning my trusty SoYouStart server (Part of OVH) so I thought I'd best document some of the stuff that may be useful in future.

You can purchase additional IP addresses off SoYouStart (SYS) however they work a little differently to the norm. I think the best way to describe it is they use static ARP to associate a public IP with a MAC address, and drop any traffic from a public IP unless its originating from the same MAC that was statically mapped. Because of this, the gateway isn't in the same subnet as the public IP range.

Before being decommissioned I was using the server as a VM Host and to mimic a 'real' setup I wanted a virtualised router / firewall between the internet and the Virtual Machines. Those of you that follow my blog will know I am a Mikrotik fanboy, so I decided to use the Mikrotik CHR (Cloud Hosted Router) as it was cheap and flexible.

To get this working I purchased an additional /32 for the routers 'external' interface and a /28 for the routers 'internal' interface. It's also required to reconfigure the SYS server's network configuration to use a bridge rather than having its IP directly on the interface.

Disclaimer: This is not a full guide, and should be considered "inspiration"

Converting a CM108 USB fob for amateur radio use

The CM108 USB audio chip has become a popular choice for Amateur Radio usage, due to its cheap price, good performance, and its exposed GPIO pins. The GPIOs can be utilised for triggering the PTT and detecting COS (When the radio is receiving a valid signal)

Due to its popularity, it has been integrated into app_rpt, a channel driver for Asterisk aimed at repeater usage, used in the popular AllStar Asterisk distribution and also supported in Hamlib, a "standardised API to control any radio oriented equipment through a computer interface", which Direwolf conveniently supports.

The following guide documents how to convert one for use with a radio. This is not my design, but the combined work of WB6NIL (SK), W9SH, M0NFI, G7RPG and many others. Pictures supplied with permission from M0NFI


Using darkcast and icecast to stream audio from a Linux ALSA audio interface on Debian

This is a quick and dirty guide to streaming audio from a sound card, physical or otherwise to the internet as an MP3 stream. I am using a new, stock Debian 9 installation and the ALSA audio driver.

Darkice captures from the sound card and pushes it to Icecast. Icecast then streams the audio to connected clients. I am also using nginx to prevent users accessing the admin interface, for a layer of security.

As this is a quick and dirty guide, its assumed you have some Linux experience. If you get stuck, feel free to leave a comment.