1.\" @(#) $FreeBSD$ (LBL) 2.\" 3.\" Copyright (c) 1990, 1991, 1993 The Regents of the University of 4.\" California. All rights reserved. 5.\" 6.\" Redistribution and use in source and binary forms, with or without 7.\" modification, are permitted provided that: (1) source code distributions 8.\" retain the above copyright notice and this paragraph in its entirety, (2) 9.\" distributions including binary code include the above copyright notice and 10.\" this paragraph in its entirety in the documentation or other materials 11.\" provided with the distribution, and (3) all advertising materials mentioning 12.\" features or use of this software display the following acknowledgement: 13.\" ``This product includes software developed by the University of California, 14.\" Lawrence Berkeley Laboratory and its contributors.'' Neither the name of 15.\" the University nor the names of its contributors may be used to endorse 16.\" or promote products derived from this software without specific prior 17.\" written permission. 18.\" THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED 19.\" WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF 20.\" MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. 21.\" 22.Dd July 19, 1993 23.Dt RARPD 8 24.Os 25.Sh NAME 26.Nm rarpd 27.Nd reverse ARP daemon 28.Sh SYNOPSIS 29.Nm 30.Op Fl adfsv 31.Op Ar interface 32.Sh DESCRIPTION 33.Nm 34services Reverse ARP requests on the Ethernet connected to 35.Ar interface . 36Upon receiving a request, 37.Nm 38maps the target hardware address to an IP address via its name, which 39must be present in both the 40.Xr ethers 5 41and 42.Xr hosts 5 43databases. 44If a host does not exist in both databases, the translation cannot 45proceed and a reply will not be sent. 46.Pp 47By default, a request is honored only if the server 48(i.e., the host that 49.Nm 50is running on) 51can "boot" the target; that is, a file or directory matching the glob 52.Pa /tftpboot/\fIipaddr\fP* 53exists, where 54.Em ipaddr 55is the target IP address in hex. 56For example, the IP address 204.216.27.18 will be replied to if any of 57.Pa /tftpboot/CCD81B12 , 58.Pa /tftpboot/CCD81B12.SUN3 , 59or 60.Pa /tftpboot/CCD81B12-boot 61exist. 62This requirement can be overridden with the 63.Fl s 64flag (see below). 65.Pp 66In normal operation, 67.Nm 68forks a copy of itself and runs in the background. 69Anomalies and errors are reported via 70.Xr syslog 3 . 71.Pp 72The following options are available: 73.Bl -tag -width indent 74.It Fl a 75Listen on all the Ethernets attached to the system. 76If 77.Fl a 78is omitted, an interface must be specified. 79.It Fl d 80If 81.Fl f 82is also specified, 83.Nm 84logs messages to 85.Em stdout 86and 87.Em stderr 88instead of via 89.Xr syslog 3 . 90.It Fl f 91Run in the foreground. 92.It Fl s 93Supply a response to any RARP request for which an ethernet to IP address 94mapping exists; do not depend on the existence of 95.Pa /tftpboot/\fIipaddr\fP* . 96.It Fl v 97Enable verbose sysloging. 98.El 99.Sh FILES 100.Bl -tag -width /etc/ethers -compact 101.It Pa /etc/ethers 102.It Pa /etc/hosts 103.It Pa /tftpboot 104.El 105.Sh SEE ALSO 106.Xr bpf 4 107.Rs 108.%A "Finlayson, R." 109.%A "Mann, T." 110.%A "Mogul, J.C." 111.%A "Theimer, M." 112.%T "RFC 903: Reverse Address Resolution Protocol" 113.%D "June 1984" 114.%O "4 p" 115.Re 116.Sh AUTHORS 117.An -nosplit 118.An Craig Leres Aq leres@ee.lbl.gov 119and 120.An Steven McCanne Aq mccanne@ee.lbl.gov . 121Lawrence Berkeley Laboratory, University of California, Berkeley, CA. 122.Sh BUGS 123.Nm 124can depend on the DNS to resolve the name discovered from 125.Pa /etc/ethers . 126If this name is not in the DNS but is in 127.Pa /etc/hosts , 128the DNS lookup can cause a delayed RARP response, so in this situation 129it is recommended to configure 130.Xr nsswitch.conf 5 131to read 132.Pa /etc/hosts 133first. 134