NAME

       ahcpd - ad-hoc configuration daemon

SYNOPSIS

       ahcpd option...  [ -- ] interface...

DESCRIPTION

       AHCP  is a configuration protocol that can replace DHCP on networks without transitive connectivity, such
       as mesh networks.

OPTIONS

       -m multicast-address
              Specify  the  link-local   multicast   address   to   be   used   by   AHCP.    The   default   is
              ff02::cca6:c0f9:e182:5359.

       -p port
              Specify the UDP port number to be used by AHCP.  The default is 5359.

       -n     Operate  as  a  forwarder:  participate  in  the flooding protocol, but don't actually perform any
              configuration.

       -4     Only attempt to configure IPv4 addresses.

       -6     Only attempt to configure IPv6 addresses.

       -N     Do not configure DNS.

       -t time
              Specify the time, in seconds, for which leases are requested.  The default is  slightly  over  one
              hour.  Must be between five minutes and a year.

       -s script
              Specify the configuration script to run.  The default is /etc/ahcp/ahcp-config.sh.

       -d level
              Set the debug level to level (default 1).

       -i filename
              Specify  the  filename  containing this host's unique id.  The default is /var/lib/ahcp-unique-id.
              If it doesn't exist, it will be created by ahcpd.

       -c filename
              Specify the name of the configuration file.

       -C statement
              Specify a configuration statement directly on the command line.

       -D     Daemonise at startup.

       -L logfile
              Specify a file to log random ``how do you do?'' messages to.  This defaults to standard  error  if
              not daemonising, and to /var/log/ahcpd.log otherwise.

       -I pidfile
              Specify a file to write our process id to.  The default is /var/run/ahcpd.pid.

CONFIGURATION FILE FORMAT

       The  configuration  is  a  sequence of lines, each of which starts with one of the keywords below.  Blank
       lines are ignored.  Comments are introduced with an octothorp ``#'' and terminate at the end of the line.

       The following keywords are recognised:

       mode server|client|forwarder
              Specifies whether the daemon operates as a server, a client, or  a  forwarder.   If  omitted,  the
              default is to operate as a client, unless the -n flag is present on the command line.  If present,
              this must be the first line in the configuration file.

       prefix prefix
              Specifies a prefix to use  for  configuring  clients.   This  keyword  is  only  valid  in  server
              configurations, and may be specified twice, once for IPv4 and once for IPv6.

       lease-dir directory
              Specifies a directory to store lease files.  This keyword is only valid in server configurations.

       name-server address
              Specifies  the  address  of a DNS server to configure clients with.  This keyword is only valid in
              server configurations, and may be repeated multiple times.

       ntp-server address
              Specifies the address of an NTP server to configure clients with.  This keyword is only  valid  in
              server configurations, and may be repeated multiple times.

FILES

       /var/lib/ahcp-unique-id
              An  8-byte  long file containing this host's unique id.  If it doesn't exist, a new unique id will
              be generated from an interface's MAC address.

       /etc/ahcp/ahcp-config.sh
              The script that performs the actual configuration.  It will  be  passed  one  argument,  which  is
              either start or stop.

       /etc/ahcp/ahcp-local.sh
              If  this  is  an  executable script, it will be called by ahcp-config.sh just after configuring or
              deconfiguring. It will be passed one argument, which is either start or stop.

SIGNALS

       SIGUSR1
              Print ahcpd's status to standard output or to the log file.

       SIGUSR2
              Check all interfaces for status changes, then reopen the log file.

NOTES

       Since the AHCP protocol is designed for mesh networks, it doesn't have any provisions for setting routing
       parameters  such as a default gateway, the IPv4 network mask and the IPv6 list of on-link prefixes; these
       are expected to  be  provided  by  a  full-fledged  routing  protocol  for  mesh  nodes,  and  by  router
       advertisements for ordinary nodes.

       The  AHCP  server  should use NTP to synchronise its clock.  If a server instance of ahcpd doesn't detect
       time synchronisation, it will only give out  leases  for  a  short  period  of  time,  and  be  extremely
       conservative  about  releasing them.  Note that an SNTP client is not enough — ahcpd actually checks with
       the kernel for time synchronisation, so real NTP is necessary.

SEE ALSO

       dhcpcd(8), dhclient(8), babeld(8), olsrd(8), ntpd(8), The Ad-Hoc Configuration Protocol.

AUTHOR

       Juliusz Chroboczek.

                                                                                                        AHCPD(8)