.TH DHCPD 8
.SH NAME
dhcpd, dhcpleases, rarpd, tftpd \- Internet booting
.SH SYNOPSIS
.PP
.B ip/dhcpd
.RB [ -dmnprsSZ ]
.RB [ -f
.IR ndb-file ]
.RB [ -M
.IR secs ]
.RB [ -x
.IR netmtpt ]
.RB [ -Z
.IR secs ]
[
.I address
.I n
] ...
.PP
.B ip/dhcpleases
.PP
.B ip/rarpd
.RB [ -d ]
.RB [ -e
.IR etherdev ]
.RB [ -x
.IR netmtpt ]
.PP
.B ip/tftpd
.RB [ -dr ]
.RB [ -h
.IR homedir ]
.RB [ -x
.IR netmtpt ]
.SH DESCRIPTION
These programs support booting over the Internet.
They should all be run on the same server to
allow other systems to be booted.
.I Dhcpd
and
.I tftpd
are used to boot everything;
.I rarpd
is an extra piece just for Suns.
.PP
.I Dhcpd
runs the
.SM BOOTP
and
.SM DHCP
protocols.
Clients use these protocols to obtain configuration information.
This information comes from attribute/value pairs in the network database
(see
.IR ndb (6)
and
.IR ndb (8)).
DHCP requests are honored both for static addresses found in
the NDB and for dynamic addresses listed in the command line.
DHCP requests are honored if either:
.br
\- there exists an NDB entry
containing both the ethernet address of the requester and
an IP address on the originating network or subnetwork.
.br
\- a free dynamic address exists on the originating network or subnetwork.
.PP
A BOOTP request is honored if all of the following are true:
.br
\- there exists an NDB entry
containing both the ethernet address of the requester and
an IP address on the originating network or subnetwork.
.br
\- the entry contains a
.B bootf=
attribute
.br
\- the file in the
.B bootf=
attribute is readable.
.PP
Dynamic addresses are specified on the command line as a list
of addresses and number pairs.
For example,
.EX
	ip/dhcpd 10.1.1.12 10 10.2.1.70 12
.EE
directs
.I dhcpd
to return dynamic addresses 10.1.1.12 through 10.1.1.21 inclusive
and 10.2.1.70 through 10.2.1.81 inclusive.
.PP
.I Dhcpd
maintains a record of all dynamic addresses in the directory
.BR /lib/ndb/dhcp ,
one file per address.
If multiple servers have access to this common directory,
they will correctly coordinate their actions.
.PP
Attributes come from either the NDB entry for the system, the entry for its
subnet, or the entry for its network.  The system entry has precedence,
then the subnet, then the network.
The NDB attributes used are:
.TF ipmask
.TP
.B ip
the IP address
.TP
.B ipmask
the IP mask
.TP
.B ipgw
the default IP gateway
.TP
.B dom
the domain name of the system
.TP
.B fs
the default Plan 9 name server
.TP
.B auth
the default Plan 9 authentication server
.TP
.B dns
a domain name server
.TP
.B ntp
a network time protocol server
.TP
.B time
a time server
.TP
.B wins
a
.SM NETBIOS
name server
.TP
.B www
a World Wide Web proxy
.TP
.B pop3
a POP3 mail server
.TP
.B smtp
an SMTP mail server
.TP
.B bootf
the default boot file;
see
.IR ndb (6)
.PD
.PP
.I Dhcpd
will answer
.SM BOOTP
requests only if it has been specifically targeted or if it
has read access to the boot file for the requester.  That means that the requester
must specify a boot file in the request or one has to exist in NDB for
.I dhcpd
to answer.
.I Dhcpd
will answer all
.SM DHCP
requests for which it can associate an IP address with the
requester.
The options are:
.TP
.B d
Print debugging to standard output.
.TP
.B f
Specify a file other than
.B /lib/ndb/local
as the network database.
.TP
.B m
Mute: don't reply to requests, just log them and what
.I dhcpd
would have done.
.TP
.B M
Use
.I secs
as the minimum lease time for dynamic addresses.
.TP
.B n
Don't answer
.SM BOOTP
requests.
.TP
.B p
Answer
.SM DHCP
requests from
.SM PPTP
clients only.
.TP
.B r
Mute static addresses: don't reply to requests for static addresses,
just log them and what
.I dhcpd
would have done.
.TP
.B s
Sleep roughly 1 to 2 seconds before answering requests for static addresses.
This is used to make a server be a backup only.
.TP
.B S
Sleep roughly 1 to 2 seconds before answering requests for dynamic addresses.
.TP
.B x
The IP stack to use is mounted at 
.IR netmtpt .
The default is
.BR /net .
.TP
.B Z
Use
.I secs
as the minimum lease time for static addresses.
.PD
.PP
.I Dhcpleases
prints out the currently valid DHCP leases found in the
.B /lib/ndb/dhcp
directory.
.PP
.I Rarpd
performs the Reverse Address Resolution Protocol, translating
Ethernet addresses into IP addresses.
The options are:
.TP
.B d
Print debugging to standard output.
.TP
.B e
Use the Ethernet mounted at
.BI /net/ etherdev\f1.
.TP
.B x
The IP stack to use is mounted at 
.IR netmtpt .
The default is
.BR /net .
.PD
.PP
.I Tftpd
transfers files to systems that are booting.
It runs as user
.B none
and can only access files with global read permission.
.L %C
in a file name is replaced with the name of the
booting system's
.L /cfg/pxe
file.
Similarly,
.L %E
becomes the booting system's Ethernet MAC address
and
.L %I
becomes its IP address.
The options are:
.TP
.B d
Print debugging to standard output.
.TP
.B x
The IP stack to use is mounted at 
.IR netmtpt .
The default is
.BR /net .
.TP
.B h
Change directory to
.IR homedir .
The default is
.BR /lib/tftpd .
All requests for files with non-rooted file names are served starting at this
directory with the exception of files of the form
.BR xxxxxxxx.SUNyy .
These are Sparc kernel boot files where
.B xxxxxxxx
is the hex IP address of the machine requesting the kernel and
.B yy
is an architecture identifier.
.I Tftpd
looks up the file in the network database using
.I ipinfo
(see
.IR ndb (2))
and responds with the boot file specified for that particular
machine.
If no boot file is specified, the transfer fails.
.I Tftpd
supports only octet mode.
.TP
.B r
Restricts access to only those files rooted in the
.IR homedir .
.PD
.SH FILES
.BR /lib/ndb/dhcp "    directory of dynamic address files
.SH SOURCE
.B /sys/src/cmd/ip
.SH "SEE ALSO"
.IR ndb (6),
.IR 9boot (8),
.IR booting (8)
.SH BUGS
.I Dhcpd
doesn't really understand a single interface having addresses
on multiple subnets, as during renumbering of a subnet.
It will only respond with addresses on the subnet
of its primary IP address on that interface.