This is an old revision of the document!
This page contains my ideas on how to design and implement a framework for configuring (embedded) ethernet switch controllers from FreeBSD.
Many wireless router devices contain multiple Ethernet ports that are implemented by an Ethernet switch chip. These chips can often be configured in varioous ways. Interesting aspects include the port link paramters, VLAN settings, per-port and per-switch statistics. Newer switch chips contain hardware features for NAT, PPPoE processing, and similar advanced features.
Design Goals
The framework should:
- Allow an administrator to configure common aspects of the switch
- The administration interface should be generic (not switch model specific)
- Allow switch model specific configuration extensions
Abstract Switch
In order to have a generic configuration interface, the framework has the concept of an abstract switch that models the various features and configuration settings of the concrete switch chips. This abstract switch has these features:
- 2 to 32 physical ports, some of which might be internal to the device (CPU attachment)
- external ports can have PHYs for controlling link aspects
- port-based VLAN support
- .1q VLAN support with a limited number of VLANs (including tagged/untagged ports)
- .1q VLAN support with all possible VID values
- .1q Priority support and frame classification