1.\" Copyright (c) 1995 2.\" Bill Paul <wpaul@ctr.columbia.edu>. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by Bill Paul. 15.\" 4. Neither the name of the author nor the names of any co-contributors 16.\" may be used to endorse or promote products derived from this software 17.\" without specific prior written permission. 18.\" 19.\" THIS SOFTWARE IS PROVIDED BY Bill Paul AND CONTRIBUTORS ``AS IS'' AND 20.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 21.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 22.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 23.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 24.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 25.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 26.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 27.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 28.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 29.\" SUCH DAMAGE. 30.\" 31.\" $FreeBSD$ 32.\" 33.Dd April 12, 1995 34.Dt ETHERS 5 35.Os 36.Sh NAME 37.Nm ethers 38.Nd ethernet address database 39.Sh DESCRIPTION 40The 41.Nm 42database contains information regarding known 48-bit ethernet addresses 43of hosts on an Internetwork. 44The data is stored in a file called 45.Pa /etc/ethers 46in the following format: 47.Pp 48.D1 Ar ethernet-address fully-qualified-host-name 49.Pp 50Items are separated by any number of blanks and/or 51tab characters. 52A ``#'' at the start of a line indicates the 53beginning of a comment that extends to the end of the line. 54A ``+'' at 55the start of a line will cause the 56.Xr ethers 3 57library functions to use data stored in the 58.Tn NIS 59.Pa ethers.byname 60and 61.Pa ethers.byaddr 62maps in addition to the data in the 63.Pa /etc/ethers 64file. 65.Pp 66An ethernet address is expressed in 67.Tn ASCII 68form as "x:x:x:x:x:x" where 69.Ar x 70is a hexadecimal value between 0x00 and 0xFF. 71The address values 72should be in network order. 73Hostnames specified in the 74.Pa /etc/ethers 75database should correspond to entries in the 76.Xr hosts 5 77file. 78.Pp 79The 80.Fn ether_line 81function in the standard C library can be used to break individual 82lines in the 83.Pa /etc/ethers 84database into their individual components: a binary Ethernet address 85stored as an 86.Pa ether_addr 87structure, and a hostname stored as a character string. 88.Sh FILES 89.Bl -tag -width /etc/services -compact 90.It Pa /etc/ethers 91The 92.Nm 93file resides in 94.Pa /etc . 95.El 96.Sh SEE ALSO 97.Xr ethers 3 , 98.Xr yp 8 99.Sh HISTORY 100The 101.Nm 102format is based on the format used in SunOS 4.1.x. 103