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