dhcpcemu(8)						      System Manager's Manual						       dhcpcemu(8)

NAME

       dhcpcemu - Emulate a DHCP client

SYNOPSIS

       /usr/sbin/dhcpcemu  [-b]  [-q]  [-m   |	-n   |	-v]  [-dn] [-a server_address] [-c client_address] [-e hardware_address] [-h hostname] [-i
       client_identifier] [-r requested_address] [-p bootp | discover | renew | rebind | request | select | decline] [-s size]	[-t  timeout]  [-f
       file] interface

OPTIONS

       Sets the broadcast bit.	Runs quietly: display neither the contents of the incoming nor the outgoing packets.  Sets the magic cookie in the
       outgoing packet to be the CMU (-m) or the RFC1048 (-v ) value (the default).  The -n option means to use no  cookie  at	all.   The  server
       identifier field in the options of the outgoing packet is set to the IP address.  To properly emulate a client in the selecting DHCP state,
       this field is required regardless of the value given with the -p option.  Sets the ciaddr field in the packet to the  value  client_address
       or  to  the  IP	address  of the interface chosen if client_address equals 0.0.0.0.  Pretend to be at the given hardware (MAC) address. The
       chaddr field is set to hardware_address.  Unless the broadcast bit is also set, this usually means that no replies will be received, as the
       server or relay agents will normally try a link-level unicast to the phony address.  Sets the hostname option in the outgoing packet to the
       given value.  Sets the client identifier option in the outgoing packet to the given string. The string is treated literally, not as  a  hex
       representation  of  an  arbitrary  octet string.  Sets the IP address value in the outgoing packet. This option is required if the outgoing
       packet is to validly represent a client in the DHCP states selecting or rebooting or in a  DHCP	DECLINE  message.   The  string  following
       determines  the	kind  of  BOOTP  or  DHCP  packet sent, and whether the packet is broadcast or unicast.  The default is to emulate a BOOTP
       client.	Sends a packet of size octets (by default 548 octets).	Exits after timeout seconds if no responses are received.  Sets  the  file
       field in the outgoing packet to the given string.

DESCRIPTION

       The  dhcpcemu  command emulates a DHCP/BOOTP client.  Options are provided to set the most important fields in the BOOTP request packet.  A
       packet is constructed, is sent through the interface specified, and a reply awaited. The emulator exits after the first reply  is  received
       or  for	a length of time specified by the -t option. Depending on the options specified and/or the DHCP server configuration, no reply may
       in fact be forthcoming. If no timeout is specified, the emulator may be killed with any suitable asynchronous signal.   The  SIGINT  signal
       (usually generated from the keyboard with Ctrl/c) is available if dhcpcemu is running in the foreground.

       It is important to note that with the options available, it is quite possible to create an illegal packet. This is one of the primary func-
       tions of dhcpcemu; to test the behavior of servers when confronted with packets that do not conform to the standards.

RESTRICTIONS

       A cluster member should never be a DHCP client. It should always use static addressing.

       If a cluster is to support a DHCP server, there can be only one DHCP server for all the	cluster  members  using  a  common  database  with
       failover.

SEE ALSO

       RFC2031, RFC2032

																       dhcpcemu(8)