.\" Copyright (c) 1988, 1989, 1991 Carnegie Mellon University .\" .\" $NetBSD: bootptab.5,v 1.7 2012/04/21 12:27:30 roy Exp $ .\" .TH BOOTPTAB 5 "October 31, 1991" "Carnegie Mellon University" .UC 6 .SH NAME bootptab \- Internet Bootstrap Protocol server database .SH DESCRIPTION The .I bootptab file is the configuration database file for .IR bootpd , the Internet Bootstrap Protocol server. Its format is similar to that of .IR capfile (5) in which two-character case-sensitive tag symbols are used to represent host parameters. These parameter declarations are separated by colons (:), with a general format of: .PP .I " hostname:tg=value:tg=value:tg=value:" .PP where .I hostname is the actual name of a bootp client (or a "dummy entry"), and .I tg is a two-character tag symbol. Replies are returned to clients only if an entry with the client's Ethernet or IP address exists in the .I booptab file. Dummy entries have an invalid hostname (one with a "." as the first character) and are used to provide default values used by other entries via the .B tc=.dummy-entry mechanism. Most tags must be followed by an equal sign and a value as above. Some may also appear in a boolean form with no value (i.e. .RI : tg :). The currently recognized tags are: .PP .br bf Bootfile .br bs Bootfile size in 512-octet blocks .br cs Cookie server address list .br df Merit dump file .br dn Domain name .br ds Domain name server address list .br ef Extension file .br gw Gateway address list .br ha Host hardware address .br hd Bootfile home directory .br hn Send client's hostname to client .br ht Host hardware type (see Assigned Numbers RFC) .br im Impress server address list .br ip Host IP address .br lg Log server address list .br lp LPR server address list .br ns IEN-116 name server address list .br nt NTP (time) Server (RFC 1129) .br ra Reply address override .br rl Resource location protocol server address list .br rp Root path to mount as root .br sa TFTP server address client should use .br sm Host subnet mask .br sw Swap server address .br tc Table continuation (points to similar "template" host entry) .br td TFTP root directory used by "secure" TFTP servers .br to Time offset in seconds from UTC .br ts Time server address list .br vm Vendor magic cookie selector .br yd YP (NIS) domain name .br ys YP (NIS) server address .PP There is also a generic tag, .RI T n , where .I n is an RFC1084 vendor field tag number. Thus it is possible to immediately take advantage of future extensions to RFC1084 without being forced to modify .I bootpd first. Generic data may be represented as either a stream of hexadecimal numbers or as a quoted string of ASCII characters. The length of the generic data is automatically determined and inserted into the proper field(s) of the RFC1084-style bootp reply. .PP The following tags take a whitespace-separated list of IP addresses: .BR cs , .BR ds , .BR gw , .BR im , .BR lg , .BR lp , .BR ns , .BR nt , .BR ra , .BR rl , and .BR ts . The .BR ip , .BR sa , .BR sw , .BR sm , and .B ys tags each take a single IP address. All IP addresses are specified in standard Internet "dot" notation and may use decimal, octal, or hexadecimal numbers (octal numbers begin with 0, hexadecimal numbers begin with '0x' or '0X'). Any IP addresses may alternatively be specified as a hostname, causing .I bootpd to lookup the IP address for that host name using gethostbyname(3). If the .B ip tag is not specified, .I bootpd will determine the IP address using the entry name as the host name. (Dummy entries use an invalid host name to avoid automatic IP lookup.) .PP The .B ht tag specifies the hardware type code as either an unsigned decimal, octal, or hexadecimal integer or one of the following symbolic names: .B ethernet or .B ether for 10Mb Ethernet, .B ethernet3 or .B ether3 for 3Mb experimental Ethernet, .BR ieee802 , .BR tr , or .B token-ring for IEEE 802 networks, .B pronet for Proteon ProNET Token Ring, or .BR chaos , .BR arcnet , or .B ax.25 for Chaos, ARCNET, and AX.25 Amateur Radio networks, respectively. The .B ha tag takes a hardware address which may be specified as a host name or in numeric form. Note that the numeric form .I must be specified in hexadecimal; optional periods and/or a leading '0x' may be included for readability. The .B ha tag must be preceded by the .B ht tag (either explicitly or implicitly; see .B tc below). If the hardware address is not specified and the type is specified as either "ethernet" or "ieee802", then .I bootpd will try to determine the hardware address using ether_hostton(3). .PP The hostname, home directory, and bootfile are ASCII strings which may be optionally surrounded by double quotes ("). The client's request and the values of the .B hd and .B bf symbols determine how the server fills in the bootfile field of the bootp reply packet. .PP If the .B bf option is specified, its value is copied into the reply packet. Otherwise, the name supplied in the client request is used. If the .B hd option is specified, its value is prepended to the boot file in the reply packet, otherwise the path supplied in the client request is used. The existence of the boot file is NOT verified by .I bootpd because the boot file may be on some other machine. .PP The .B bs option specified the size of the boot file. It can be written as .BR bs =auto which causes .I bootpd to determine the boot file size automatically. .PP Some newer versions of .I tftpd provide a security feature to change their root directory using the .IR chroot (2) system call. The .B td tag may be used to inform .I bootpd of this special root directory used by .IR tftpd . (One may alternatively use the .I bootpd "-c chdir" option.) The .B hd tag is actually relative to the root directory specified by the .B td tag. For example, if the real absolute path to your BOOTP client bootfile is /tftpboot/bootfiles/bootimage, and .IR tftpd uses /tftpboot as its "secure" directory, then specify the following in .IR bootptab : .PP .br :td=/tftpboot:hd=/bootfiles:bf=bootimage: .PP If your bootfiles are located directly in /tftpboot, use: .PP .br :td=/tftpboot:hd=/:bf=bootimage: .PP The .B sa tag may be used to specify the IP address of the particular TFTP server you wish the client to use. In the absence of this tag, .I bootpd will tell the client to perform TFTP to the same machine .I bootpd is running on. .PP The time offset .B to may be either a signed decimal integer specifying the client's time zone offset in seconds from UTC, or the keyword .B auto which uses the server's time zone offset. Specifying the .B to symbol as a boolean has the same effect as specifying .B auto as its value. .PP The bootfile size .B bs may be either a decimal, octal, or hexadecimal integer specifying the size of the bootfile in 512-octet blocks, or the keyword .B auto which causes the server to automatically calculate the bootfile size at each request. As with the time offset, specifying the .B bs symbol as a boolean has the same effect as specifying .B auto as its value. .PP The vendor magic cookie selector (the .B vm tag) may take one of the following keywords: .B auto (indicating that vendor information is determined by the client's request), .B rfc1048 or .B rfc1084 (which always forces an RFC1084-style reply), or .B cmu (which always forces a CMU-style reply). .PP The .B hn tag is strictly a boolean tag; it does not take the usual equals-sign and value. It's presence indicates that the hostname should be sent to RFC1084 clients. .I Bootpd attempts to send the entire hostname as it is specified in the configuration file; if this will not fit into the reply packet, the name is shortened to just the host field (up to the first period, if present) and then tried. In no case is an arbitrarily-truncated hostname sent (if nothing reasonable will fit, nothing is sent). .PP Often, many host entries share common values for certain tags (such as name servers, etc.). Rather than repeatedly specifying these tags, a full specification can be listed for one host entry and shared by others via the .B tc (table continuation) mechanism. Often, the template entry is a dummy host which doesn't actually exist and never sends bootp requests. This feature is similar to the .B tc feature of .IR capfile (5) . Note that .I bootpd allows the .B tc tag symbol to appear anywhere in the host entry, unlike .I capfile which requires it to be the last tag. Information explicitly specified for a host always overrides information implied by a .B tc tag symbol, regardless of its location within the entry. The value of the .B tc tag may be the hostname or IP address of any host entry previously listed in the configuration file. .PP Sometimes it is necessary to delete a specific tag after it has been inferred via .BR tc . This can be done using the construction .IB tag @ which removes the effect of .I tag as in .IR capfile (5). For example, to completely undo an IEN-116 name server specification, use ":ns@:" at an appropriate place in the configuration entry. After removal with .BR @ , a tag is eligible to be set again through the .B tc mechanism. .PP Blank lines and lines beginning with "#" are ignored in the configuration file. Host entries are separated from one another by newlines; a single host entry may be extended over multiple lines if the lines end with a backslash (\\). It is also acceptable for lines to be longer than 80 characters. Tags may appear in any order, with the following exceptions: the hostname must be the very first field in an entry, and the hardware type must precede the hardware address. .PP An example .I /etc/bootptab file follows: .PP .nf # Sample bootptab file (domain=andrew.cmu.edu) .default:\\ :hd=/usr/boot:bf=null:\\ :ds=netserver, lancaster:\\ :ns=pcs2, pcs1:\\ :ts=pcs2, pcs1:\\ :sm=255.255.255.0:\\ :gw=gw.cs.cmu.edu:\\ :hn:to=-18000: carnegie:ht=6:ha=7FF8100000AF:tc=.default: baldwin:ht=1:ha=0800200159C3:tc=.default: wylie:ht=1:ha=00DD00CADF00:tc=.default: arnold:ht=1:ha=0800200102AD:tc=.default: bairdford:ht=1:ha=08002B02A2F9:tc=.default: bakerstown:ht=1:ha=08002B0287C8:tc=.default: # Special domain name server and option tags for next host butlerjct:ha=08002001560D:ds=128.2.13.42:\\ :T37=0x12345927AD3BCF:\\ :T99="Special ASCII string":\\ :tc=.default: gastonville:ht=6:ha=7FFF81000A47:tc=.default: hahntown:ht=6:ha=7FFF81000434:tc=.default: hickman:ht=6:ha=7FFF810001BA:tc=.default: lowber:ht=1:ha=00DD00CAF000:tc=.default: mtoliver:ht=1:ha=00DD00FE1600:tc=.default: .fi .SH FILES /etc/bootptab .SH "SEE ALSO" .br bootpd(8), tftpd(8), .br DARPA Internet Request For Comments RFC951, RFC1048, RFC1084, Assigned Numbers