.\" Copyright (c) 1983, 1991 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)ddn.4	6.5 (Berkeley) 03/27/91
.\"
.Dd 
.Dt DDN 4 vax
.Os BSD 4.3
.Sh NAME
.Nm ddn
.Nd
.Tn DDN
Standard Mode
.Tn X.25
.Tn IMP
interface
.Sh SYNOPSIS
.Cd "device ddn0 at uba0 csr 166740 vector ddnintr"
.Sh DESCRIPTION
The 
.Nm ddn
device provides a
.Tn DDN
Standard Mode
.Tn X.25
interface to an
.Tn IMP
using
the
.Tn ACC ACP625
.Tn X.25
board.  It is normally used for connecting to
the Defense Data Network
.Pq Tn DDN .
The controller itself is not accessible
to users, but instead provides a network interface for the
Internet Protocol described in
.Xr ip 4 .
.Sh DIAGNOSTICS
.Bl -diag
.It ddn%d: not alive.
The initialization routine was entered even though the device
did not autoconfigure.  This indicates a system problem.
.Pp
.It ddn%d: failed getting UBA resources for lcn %d."
Insufficient
.Tn UNIBUS
resources existed to initialize the device.
This is likely to be a shortage of
.Tn UNIBUS
mapping registers.
.Pp
.It ddn%d: couldn't get X25 init buffer.
This indicates that an 
.Em mbuf
could not be allocated for sending the initialization message to the
.Tn ACP Ns 625.
.Pp
.It DDN: illegal X25 address length!
.It DDN: illegal X25 address format!
These errors indicate a problem with the called
.Tn X.25
address received
from the
.Tn IMP
on an incoming call.
.Pp
.It X25 RESET on lcn = %d.
This indicates that an unexpected
.Tn X.25
.Tn RESET
was received on the
indicated
.Tn LCN .
.Pp
.It X25 INTERRUPT on lcn = %d, code = %d.
This indicates that an unexpected
.Tn X.25
.Tn INTERRUPT
Packet was received on the
indicated
.Tn LCN .
.Pp
.It ddn%d: failed to get supr msg bfr!
This indicates that an 
.Em mbuf
could not be allocated for sending a supervisor message to the
.Tn ACP625 .
.El
.Pp
Any other error message from
.Ql ddn%d:
indicates a serious error
detected by either the driver or the
.Tn ACP Ns 625
firmware.
.Sh SEE ALSO
.Xr netintro 4 ,
.Xr ip 4
.Sh HISTORY
The
.Nm
interface appeared in
.Bx 4.3 .