ipallocd - Ethernet-to-IP address allocator
Available only on Sun 386i systems running a SunOS 4.0.x release or
earlier. Not a SunOS 4.1 release feature.
ipallocd is a daemon that determines or temporarily allocates IP
addresses within a network segment. The service is only available on
the system which is home to the address authority for the network seg-
ment, currently the Network Information Service (NIS) master of the
hosts.byaddr map although the service is not tied to the NIS service.
It has complete knowledge of the hosts listed in the NIS service, and,
if the system is running the name server, of any hosts listed in inter-
net domain tables automatically accessed on that host through the stan-
dard library gethostent(3N) call.
This protocol uses DES authentication (the Sun Secure RPC protocol) to
restrict access to this function. The only clients privileged to allo-
cate addresses are those whose net IDs are in the networks group. For
machine IDs, the machine must be an NIS server.
The daemon uses permanent entries in the /etc/ethers and /etc/hosts
files when they exist and are usable. In other cases, such as when a
system is new to the network, ipallocd enters a temporary mapping in a
local cache. Entries in the cache are removed when there have been no
references to a given entry in the last hour. This cache survives sys-
tem crashes so that IP addresses remain consistent.
The daemon also provides corresponding IP address to name mapping.
If the file /etc/ipalloc.netrange exists, ipallocd refuses to allocate
addresses on networks not listed in the netrange file, or for which no
free address is available.
/etc/ipalloc.cache temporary cache
optional file to allocate network addresses
ipalloc(3R), pnp(3R), ipalloc.netrange(5), ipallocd(8C), netconfig(8C),
The Network Information Service (NIS) was formerly known as Sun Yellow
Pages (YP). The functionality of the two remains the same; only the
name has changed.
4 December 1987 IPALLOCD(8C)