
BAH(4)                OpenBSD Programmer's Manual (Amiga)               BAH(4)

NAME
     bah - ARCnet driver for SMC COM90C26 based boards

SYNOPSIS
     bah* at zbus0

DESCRIPTION
     The bah interface provides access to the 2.5 Mb/s ARCnet network via the
     SMC COM90C26 ARCnet chip set.

     Each of the host's network addresses is specified at boot time with an
     SIOCSIFADDR ioctl. The bah interface does not employ the address resolu-
     tion protocol described in arp(4) to dynamically map between Internet and
     Ethernet addresses on the local network.  Instead, it uses the least sig-
     nificant 8 bits of the IP address as hardware address, as described in
     RFC(1051) and RFC(1201) as one option.

     With the IFF_LINK0 flag cleared, IP encoding is done according to the
     deprecated, but popular among Amiga users, RFC 1051 encoding (that is,
     with simple header, packet type 240), and the MTU is 507.

     With the IFF_LINK0 flag set, IP encoding is done according to RFC 1201
     (that is, with Packet Header Definition Standard header and packet type
     212).  The MTU is normally 1500.

     When switching between the two modes, do a
     ifconfig interfacename down up to switch the mtu.

HARDWARE
     The bah interface supports the following Zorro II expansion cards:

           A2060      Commodore's arcnet card, manufacturer 514, product 9

           AMERISTAR  Ameristar's arcnet card, manufacturer 1053, product 9

SEE ALSO
     arp(4), inet(4), intro(4), ifconfig(8) RFC1051 , RFC1201
     ARCnet Packet Header Definition Standard, Novell Inc., 1989

STANDARDS
     RFC 1051 / RFC1201 without ARP, using direct mapping of lower 8 IP ad-
     dress bits instead.

HISTORY
     The Amiga bah interface first appeared in NetBSD 1.0A

AUTHORS
     Ignatios Souvatzis

OpenBSD 3.0                      May 31, 1995                                1
