1.\" $NetBSD: bah.4,v 1.14 2002/01/15 01:24:10 wiz Exp $ 2.\" 3.\" Copyright (c) 1995, 1997 The NetBSD Foundation, Inc. 4.\" All rights reserved. 5.\" 6.\" This code is derived from software contributed to The NetBSD Foundation 7.\" by Ignatios Souvatzis. 8.\" 9.\" Redistribution and use in source and binary forms, with or without 10.\" modification, are permitted provided that the following conditions 11.\" are met: 12.\" 1. Redistributions of source code must retain the above copyright 13.\" notice, this list of conditions and the following disclaimer. 14.\" 2. Redistributions in binary form must reproduce the above copyright 15.\" notice, this list of conditions and the following disclaimer in the 16.\" documentation and/or other materials provided with the distribution. 17.\" 3. All advertising materials mentioning features or use of this software 18.\" must display the following acknowledgement: 19.\" This product includes software developed by the NetBSD 20.\" Foundation, Inc. and its contributors. 21.\" 4. Neither the name of The NetBSD Foundation nor the names of its 22.\" contributors may be used to endorse or promote products derived 23.\" from this software without specific prior written permission. 24.\" 25.\" THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS 26.\" ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED 27.\" TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 28.\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS 29.\" BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 30.\" CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 31.\" SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 32.\" INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 33.\" CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 34.\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 35.\" POSSIBILITY OF SUCH DAMAGE. 36.\" 37.\" The following requests are required for all man pages. 38.Dd May 31, 1995 39.Os 40.Dt BAH 4 amiga 41.Sh NAME 42.Nm bah 43.Nd ARCnet network driver for SMC COM90C26 based boards 44.Sh SYNOPSIS 45.Cd "bah* at zbus0" 46.Sh DESCRIPTION 47The 48.Nm 49interface provides access to the 2.5 Mb/s ARCnet network via the 50.Tn SMC 51COM90C26 + COM90C32 52ARCnet chip set. 53.Pp 54Each of the host's network addresses 55is specified at boot time with an 56.Dv SIOCSIFADDR 57.Xr ioctl 2 . 58The interface MTU is 507 for protocols that do not use link level fragmentation 59and 60480 bytes for the others. The routing layer may specify additional 60limits. 61.br 62Currently supported protocols are IPv4(+ARP), and IPv6. 63.Sh IP VERSION 4 CONSIDERATIONS 64When the NOARP flag is set on the 65.Nm 66interface, 67it does not employ the address resolution protocol described in 68.Xr arp 4 69to dynamically map between Internet and Ethernet addresses on the local 70network. Instead, it uses the least significant 8 bits of the IP address 71as hardware address, as described in RFC 1051 and RFC 1201. 72.Pp 73With the IFF_LINK0 flag cleared, IP and ARP encoding is done according to the 74deprecated, but popular among Amiga users, RFC 1051 encoding (that 75is, with simple header, packet type 240 / 241), and the MTU is 507. 76.Pp 77With the IFF_LINK0 flag set, IP/ARP/RARP encoding is done according to RFC 1201 78(that is, with Packet Header Definition Standard header and packet type 79212/213). The MTU is normally 1500. 80.Pp 81When switching between the two modes, do a 82.Cd ifconfig interfacename down up 83to switch the mtu. 84.Pp 85When the IFF_LINK2 flag is set, ARP packets are sent with the protocol type 86encoded as it would be in the ARCnet header, and decoded to the right protocol 87encoding on reception. According to "assigned numbers", this is wrong, but 88some legacy software (namely, AmiTCP 3.0beta) shows this bug. 89.Sh HARDWARE 90The 91.Nm 92interface supports the following Zorro II expansion cards: 93.Bl -tag -width "AMERISTAR" -offset indent 94.It Em A2060 95Commodore's ARCnet card, manufacturer\ 514, product\ 9 96.It Em AMERISTAR 97Ameristar's ARCnet card, manufacturer\ 1053, product\ 9 98.El 99.Sh SEE ALSO 100.Xr arp 4 , 101.Xr inet 4 , 102.Xr intro 4 , 103.Xr ifconfig 8 104.Rs 105.%J RFC 106.%N 1051 107.%D March 1988 108.%T "Standard for the transmission of IP datagrams and ARP packets over ARCNET networks." 109.%A P.A. Prindeville 110.Re 111.Rs 112.%J RFC 113.%N 1201 114.%T "Transmitting IP traffic over ARCNET networks." 115.%A D. Provan 116.%D February 1991 117.Re 118.Rs 119.%J RFC 120.%N 2497 121.%T "Transmission of IPv6 Packets over ARCnet Networks." 122.%A I. Souvatzis 123.%D January 1999 124.Re 125.Pp 126ARCnet Packet Header Definition Standard, Novell Inc., 1989 127.Sh STANDARDS 128RFC 1051/RFC1201 with ARP, or without, using direct mapping of lower 8 IP 129address bits instead. 130.Sh HISTORY 131The 132.Tn Amiga 133.Nm 134interface first appeared in 135.Nx 1.1 . 136ARP support was added in 137.Nx 1.3 . 138.Sh AUTHORS 139.An Ignatios Souvatzis 140