RARPD(8) BSD System Manager's Manual RARPD(8)NAMErarpd - Reverse ARP Daemon
SYNOPSISrarpd [-dfA] [-t timeout] interface [address]
rarpd-a [-dfA] [-t timeout] interface
rarpd-a [-dfA] [-t timeout]
DESCRIPTION
Rarpd services Reverse ARP requests on attached Ethernet networks. Upon
receiving a request, rarpd translates the target hardware address to a
hostname (via /etc/ethers) and then to an IP address via the nameserver
(see gethostbyname(3) and hostname(7)). If either translation fails, no
reply will be sent.
Additionally, unless the -A flag is set, a request is honored only if the
server (i.e., the host that rarpd is running on) can ``boot'' the target;
that is, if a file starting with /tftpboot/ipaddr exists, where ipaddr is
the target IP address (in host byte order) expressed in hexadecimal.
In normal operation, rarpd forks a copy of itself and runs in the back-
ground. Anomalies and errors are reported via syslog(3).
Rarpd responds to queries on one or more Ethernet networks, as config-
ured. Specific Ethernet networks are configured by specifying the sym-
bolic interface name (e.g. ``ef0'' or ``de1'' ). Ethernet networks are
configured with one or more IP networks (see ifconfig(8)) and rarpd can
be configured to answer requests for IP addresses on one or all of these
IP networks. A specific IP network is selected by it specifying the in-
terface address on that network as a Internet hostname or dotted quad In-
ternet address.
In the first synopsis rarpd runs only the specified interface, if an
address is not specified, the first address on the interface is used. In
the second synopsis rarpd runs on all addresses configured on interface.
In the third synopsis rarpd runs on all addresses on all Ethernet net-
works configured on the system.
If a combination of the available configuration options is needed, multi-
ple copies of the rarpd daemon may be started.
The options recognized by rarpd are as follows:
-a Used with an interface specification, requests for addresses on all
IP networks configured for the specified Ethernet network are pro-
cessed. Used with no interface specification, requests for address-
es on all IP networks configured on all Ethernet networks are pro-
cessed.
-d Run in debug mode, with debugging output on stderr. This option im-
plies the -f option.
-f Run in the foreground.
-t timeout
Specify the time interval at which rarpd should check for changes in
interface configuration. Defaults to five minutes.
-A Do not check for a boot file in /tftpboot
/etc/ethers
~ The format of the /etc/ethers file is an Ethernet address specified as
six hexadecimal bytes (one or two digits each) followed whitespace and an
IP hostname specified as a symbolic hostname or dotted quad.
FILES
/etc/ethers
/etc/hosts
/tftpboot
SEE ALSObpf(4), syslog(3), ifconfig(8),
Finlayson, R., Mann, T., Mogul, J.C., and Theimer, M., A Reverse Address
Resolution Protocol, RFC 903.
AUTHORS
Craig Leres (leres@ee.lbl.gov) and Steven McCanne (mccanne@ee.lbl.gov).
Lawrence Berkeley Laboratory, University of California, Berkeley, CA.
BUGS
The /etc/ethers file should be documented separately.
The use of hexadecimal representation of IP addresses in /tftpboot is
awkward at best.
October 26, 1990 2
