These changes were made in order to export information about the driver and
the network that the SNMP agent must report. The changes were trivial in
the case of the network stack, since it was already SNMP-friendly. The
generic ethernet device driver was re-organized to have an extensive header
file and to add a couple of APIs to extract statistics that the
hardware-specific device drivers keep within themselves.
There may be a performance hit for recording that data; disabling
a config option named something like
CYGDBG_DEVS_ETH_xxxx_xxxx_KEEP_STATISTICS
depending on the specific device driver will prevent that.
Not all platform ethernet device drivers export complete SNMP statistical
information; if the exported information is missing, SNMP will report zero
values for such data (in the dot3 MIB).
The interface chipset has an ID which is an OID; not all the latest greatest
devices are listed in the available database, so new chipsets may need to
be added to the client MIB, if not defined in those from UCD.