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en(4) [bsd man page]

EN(4)							     Kernel Interfaces Manual							     EN(4)

NAME
en - Xerox 3 Mb/s Ethernet interface SYNOPSIS
/sys/conf/SYSTEM: NEN en_controllers # Xerox prototype (3 Mb) Ethernet DESCRIPTION
The en interface provides access to a 3 Mb/s Ethernet network. Due to limitations in the hardware, DMA transfers to and from the network must take place in the lower 64K bytes of the UNIBUS address space, and thus this must be among the first UNIBUS devices enabled after boot. Each of the host's network addresses is specified at boot time with an SIOCSIFADDR ioctl. The station address is discovered by probing the on-board Ethernet address register, and is used to verify the protocol addresses. No packets will be sent or accepted until a network address is supplied. The interface software implements an exponential backoff algorithm when notified of a collision on the cable. This algorithm utilizes a 16-bit mask and the VAX-11's interval timer in calculating a series of random backoff values. The algorithm is as follows: 1. Initialize the mask to be all 1's. 2. If the mask is zero, 16 retries have been made and we give up. 3. Shift the mask left one bit and formulate a backoff by masking the interval timer with the mask (this is actually the two's complement of the value). 4. Use the value calculated in step 3 to delay before retransmitting the packet. The interface handles both Internet and NS protocol families. It normally tries to use a ``trailer'' encapsulation to minimize copying data on input and output. The use of trailers is negotiated with ARP. This negotiation may be disabled, on a per-interface basis, by set- ting the IFF_NOTRAILERS flag with an SIOCSIFFLAGS ioctl. DIAGNOSTICS
en%d: output error. The hardware indicated an error on the previous transmission. en%d: send error. After 16 retransmissions using the exponential backoff algorithm described above, the packet was dropped. en%d: input error. The hardware indicated an error in reading a packet off the cable. en%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
intro(4N), inet(4F) BUGS
The device has insufficient buffering to handle back to back packets. This makes use in a production environment painful. The hardware does word at a time DMA without byte swapping. To compensate, byte swapping of user data must either be done by the user or by the system. A kludge to byte swap only IP packets is provided if the ENF_SWABIPS flag is defined in the driver and set at boot time with an SIOCSIFFLAGS ioctl. 3rd Berkeley Distribution August 20, 1987 EN(4)

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xna(4)							     Kernel Interfaces Manual							    xna(4)

Name
       xna - DEBNI and DEMNA Ethernet interfaces

Syntax
       device xna0 at vaxbi? node? vector xnaintr (DEBNI)
       device xna0 at xmi? node? vector xnaintr (DEMNA)

Description
       The  driver provides access to a 10 Mbytes Ethernet network through the DEBNI and DEMNA adapters.  The DEBNI is an Ethernet to BI bus.  The
       DEMNA is an Ethernet to XMI adapter.

       The host's Internet address is specified at boot time with an SIOCSIFADDR ioctl.  The driver employs the Address  Resolution  Protocol,	as
       described in to map dynamically between Internet and Ethernet addresses on the local network.

       The  driver normally tries to use a trailer encapsulation to minimize copying data on input and output.	This can be disabled for an inter-
       face by setting the IFF_NOTRAILERS flag with an SIOCSIFFLAGS ioctl.  Trailers are used only for packets destined for Internet hosts.

       The SIOCSPHYSADDR ioctl can be used to change the physical address of the adapter and SIOCRPHYSADDR  can  be  used  to  read  its  physical
       address.   SIOCADDMULTI	and  SIOCDELMULTI can be used to add or delete multicast addresses.  The driver supports a maximum of 12 multicast
       addresses. The argument to the latter ioctls is a pointer to an ``ifreq'' structure found in

       SIOCRDCTRS and SIOCRDZCTRS ioctls can be used to read or read and clear network counters. The argument  to  the	latter	two  ioctls  is  a
       pointer to a counter structure ``ctrreq'' found in

       The ioctls SIOCENABLBACK and SIOCDISABLBACK can be used to enable and disable the interface loopback mode.

Restrictions
       The PUP protocol family is not supported.

Diagnostics
       xna%d: port self-test failed:<register list>
       Adapter did not pass the power-up self-test during autoconfiguration time. The port attachment fails.

       xna%d: couldn't allocate...
       The driver was unable to allocate memory for adapter data structures.  The port attachment fails.

       xna%d: port probe failed:<register list>
       The driver was unable to bring the adapter into the initialized state.  The port attachment fails.

       xna%d: port init failed:<register list>
       The driver failed to prepare the adapter for runtime use.

       xna%d: port state changed, resetting:<register list>
       The adapter issued a port state change interrupt. The port state is reset.

       xna%d: port reset failed
       The driver was unable to bring the adapter into the initialized state during a port reset.

       xna%d: command failed, error code:<error code>
       The adapter port command failed. The error code gives reason for failure.

       xna%d: couldn't handle af%d
       A packet with an undefined protocol type has been sent to the adapter.

       xna%d: addmulti failed, multicast list full
       Too many multicast requests have been made.

See Also
       arp(4p), inet(4f), intro(4n)

																	    xna(4)
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