Automatic Best Connection Chooser - simple daemon to choose the best connection in Linux system.

The abcc is simple daemon written in Python. It periodically measures quality of the internet connections defined in the configuration file. In order to do this, it temporarily sets, with the help of plugin scripts, routing to defined IP via currently tested interface.

When all interfaces are tested, the best is chosen and given routing is set to this interface. Routing switching is also done by helper scripts (plugins) written in Bash.

The abcc is fully customizable, interface and route aware, so only routes available on given interface will be set on that interface. User can set weights of parameters and IPs in the configuration file. Logs are send to syslog.

You can find some motivation and history on my blog (PL). First post about this project: https://zakr.es/blog/2017/03/geneza-nazwa-i-zastosowania/

• GNU/Linux
• Python 2.7 (because of ping module)
• modules listed in requirements.txt

Installation

• virtualenv venv_abcc
• source ./venv_abcc/bin/activate
• pip install -r requirements.txt
• adjust config file

Configuration is performed by YAML configruation file, which can be specified by --config parameter. Example configuration is provided in example.yaml.

It has two main blocks: interfaces and routes

The first one contains interfaces names. Each interface has to have set gateway of the interface and list of routes available on given iterface. Each route has to be defined in the routes section.

The second one contains information how given route should be tested and how score for this route should be counted. There are three optional global parameters:

• loss_mult - loss multiplier, which tells how much packet loss counts for given route
• lag_mult - lag multiplier, which tells how much delay is important for given route
• switch_cost - which prevents switching routing when score difference is too low

For each route there are defined IPs, which will be tested (pinged). Each IP can have optional parameters:

• multipliers, which increases importance of all results for that IP
• count, which tells how many packets should be send to that IP
• switch_cost, which prevents routing changes on small differences between interfaces

• lag multiplier = 1
• loss multiplier = 10
• count = 10
• route change cost - 100

• clone this repository
• pip install -r requirements.txt
• adjust config file (see example.yaml)
• run as root with --dry-run (-d) and change logs (root required for ICMP and routing changes)

Help is always welcome, so clone this repository, send pull requests or create issues if you find any bugs.

See LICENSE file