1AHCPD(8) System Manager's Manual AHCPD(8)
2
6 ahcpd - ad-hoc configuration daemon
7
9 ahcpd option... [ -- ] interface...
10
12 AHCP is a configuration protocol that can replace DHCP on networks
13 without transitive connectivity, such as mesh networks.
14
16 -m multicast-address
17 Specify the link-local multicast address to be used by AHCP.
18 The default is ff02::cca6:c0f9:e182:5359.
19 -p port
21 Specify the UDP port number to be used by AHCP. The default is
22 5359.
23 -n Operate as a forwarder: participate in the flooding protocol,
25 but don't actually perform any configuration.
26 -4 Only attempt to configure IPv4 addresses.
28 -6 Only attempt to configure IPv6 addresses.
30 -N Do not configure DNS.
32 -t time
34 Specify the time, in seconds, for which leases are requested.
35 The default is slightly over one hour. Must be between five
36 minutes and a year.
37 -s script
39 Specify the configuration script to run. The default is
40 /etc/ahcp/ahcp-config.sh.
41 -d level
43 Set the debug level to level (default 1).
44 -i filename
46 Specify the filename containing this host's unique id. The
47 default is /var/lib/ahcp-unique-id. If it doesn't exist, it
48 will be created by ahcpd.
49 -c filename
51 Specify the name of the configuration file.
52 -C statement
54 Specify a configuration statement directly on the command line.
55 -D Daemonise at startup.
57 -L logfile
59 Specify a file to log random ``how do you do?'' messages to.
60 This defaults to standard error if not daemonising, and to
61 /var/log/ahcpd.log otherwise.
62 -I pidfile
64 Specify a file to write our process id to. The default is
65 /var/run/ahcpd.pid.
66
68 The configuration is a sequence of lines, each of which starts with one
69 of the keywords below. Blank lines are ignored. Comments are intro‐
70 duced with an octothorp ``#'' and terminate at the end of the line.
71 The following keywords are recognised:
73 mode server|client|forwarder
75 Specifies whether the daemon operates as a server, a client, or
76 a forwarder. If omitted, the default is to operate as a client,
77 unless the -n flag is present on the command line. If present,
78 this must be the first line in the configuration file.
79 prefix prefix
81 Specifies a prefix to use for configuring clients. This keyword
82 is only valid in server configurations, and may be specified
83 twice, once for IPv4 and once for IPv6.
84 lease-dir directory
86 Specifies a directory to store lease files. This keyword is
87 only valid in server configurations.
88 name-server address
90 Specifies the address of a DNS server to configure clients with.
91 This keyword is only valid in server configurations, and may be
92 repeated multiple times.
93 ntp-server address
95 Specifies the address of an NTP server to configure clients
96 with. This keyword is only valid in server configurations, and
97 may be repeated multiple times.
98
100 /var/lib/ahcp-unique-id
101 An 8-byte long file containing this host's unique id. If it
102 doesn't exist, a new unique id will be generated from an inter‐
103 face's MAC address.
104 /etc/ahcp/ahcp-config.sh
106 The script that performs the actual configuration. It will be
107 passed one argument, which is either start or stop.
108 /etc/ahcp/ahcp-local.sh
110 If this is an executable script, it will be called by ahcp-con‐
111 fig.sh just after configuring or deconfiguring. It will be
112 passed one argument, which is either start or stop.
113
115 SIGUSR1
116 Print ahcpd's status to standard output or to the log file.
117 SIGUSR2
119 Check all interfaces for status changes, then reopen the log
120 file.
121
123 Since the AHCP protocol is designed for mesh networks, it doesn't have
124 any provisions for setting routing parameters such as a default gate‐
125 way, the IPv4 network mask and the IPv6 list of on-link prefixes; these
126 are expected to be provided by a full-fledged routing protocol for mesh
127 nodes, and by router advertisements for ordinary nodes.
128 The AHCP server should use NTP to synchronise its clock. If a server
130 instance of ahcpd doesn't detect time synchronisation, it will only
131 give out leases for a short period of time, and be extremely conserva‐
132 tive about releasing them. Note that an SNTP client is not enough —
133 ahcpd actually checks with the kernel for time synchronisation, so real
134 NTP is necessary.
135
137 dhcpcd(8), dhclient(8), babeld(8), olsrd(8), ntpd(8), The Ad-Hoc Con‐
138 figuration Protocol.
139
141 Juliusz Chroboczek.
142 AHCPD(8)