2 =======================================
11 =======================================
12 This application provides means to check the availability of remote hosts
13 through pings to them.
17 ---------------------------------------
18 The application uses ICMP echo requests messages, or TCP segments to verify
19 whether a given host is available (up) or not (down).
21 The host's address can be an IP or a DNS.
25 ---------------------------------------
26 There are many ways to invoke the application, the simplest is just type:
28 which uses the configuration values from the configuration file (described in
29 the Configuration File section).
33 ---------------------------------------
34 Further information about the problem domain can be found in the References
39 ---------------------------------------
40 Most parts are licensed under the GPLv2 + linking exception.
42 The ICMP code, bost::net::dns and the "boost pinger" are licensed under the
43 boost license and include a note about this in the beginning of the source code.
47 =======================================
48 In this section are described the configuration items, along with they possible
49 values and meanings. This section is organized in each major configuration
54 ---------------------------------------
55 This configurations are shared among and affect all the hosts.
56 - source-network-interface: the local network interface from where the ping
57 packages with originate.
58 - nameserver: the server which the hosts names will be resolved. It is the
59 lookup server which the application will query first. If left blank or omited,
60 it will use the /etc/resolv.conf.
61 You can use the nslookup <host> to figure out the nameserver.
62 - hosts-down-limit: an absolute number, which ranges from 0 to the number of
63 hosts available. This value represents the minimum number of hosts that have
64 to fail (i.e. do not reply to the ping) in order to alert any external system.
65 - ping-fail-limit: percentage of pings to a host that can fail. If the
66 percentage of failed pings to a host exceed this number, then the host is
68 - status-notifier-cmd: the command line that is called when a host is down, or
69 up. Accepted variables are:
70 ${status} - down or up
71 - link-up-interval: how long (in minutes) the pings must be returned with
72 success in order to consider the link up, or stable.
73 - link-down-interval: how long (in minutes) the pings must fail, in order to the
74 application consider the link down.
78 ---------------------------------------
79 - name: the DNS or IP of the host to ping. Take in consideration that, if a
80 DNS is given, the application pings all IPs in the look up table, however, if
81 IP is provide, it is the only which will be pinged.
82 - port: when using a port based protocol, like TCP, this field specifies in
83 which port to ping the host.
84 - interval: the host will be pinged every "interval" seconds.
85 - ping-protocol: indicates which protocol to use to ping the destination host,
86 the currently supported protocols are TCP (tcp, tcp_ipv6) and ICMP (icmp, icmpv6).
87 This configuration can be used to perform a protocol fallback, in which N pings
88 are performed with one protocol, and then after those N attempts, a second protocol
89 is used. For example, with the given configuration:
90 ping-protocol=ICMPv6,42,ICMP
91 the program will ping a host 42 times using the ICMP over IPv6, and then it will
92 use the ICMP over IPv4 after those 42 attempts.
97 =======================================
98 The command line accepts the general configuration file options plus the
100 - config-file: command line to specify a file where the hosts and other
101 configuration information are provided.
102 - daemon: run the application as a daemon.
103 - log-level: apply a filter of which log messages will be printed. The available
104 options are the default Unix levels (e.g. debug, info, etc.).
109 =======================================
110 [1] http://tools.ietf.org/html/rfc792
111 [2] http://en.wikipedia.org/wiki/Ping
112 [3] http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
113 [4] http://www.boost.org/doc/libs/1_45_0/doc/html/boost_asio.html
114 [5] http://www.boost.org/doc/libs/1_45_0/doc/html/program_options.html
115 [6] http://www.networkuptime.com/nmap/page4-4.shtml