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)