EC(4S)

NAME
ec - 3Com 10 Mb/s Ethernet interface

CONFIG — SUN-2 SYSTEM
device ec0 at mbmem ? csr 0xe0000 priority 3
device ec1 at mbmem ? csr 0xe2000 priority 3

DESCRIPTION

The ec interface provides access to a 10 Mb/s Ethernet network through a 3COM controller. For a general description of network interfaces see if(4N).

The hardware consumes 8 kilobytes of Multibus memory space. This memory is used for internal buffering by the board. The board starts at standard addresses 0xE0000 or 0xE2000. The board must be configured for interrupt level 3.

The interface software implements an exponential backoff algorithm when notified of a collision on the cable.

The interface handles the Internet protocol family, with the interface address maintained in Internet format. The Address Resolution Protocol arp(4P) is used to map 32-bit Internet addresses used in inet(4F) to the 48-bit addresses used on the Ethernet.

DIAGNOSTICS

ec%d: Ethernet jammed
    After 16 failed transmissions and backoffs using the exponential backoff algorithm, the packet was dropped.

ec%d: can't handle af%d
    The interface was handed a message with addresses formatted in an unsuitable address family; the packet was dropped.

SEE ALSO
arp(4P), if(4N), inet(4F)

BUGS
The interface hardware is not capable of talking to itself, making diagnosis more difficult.