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 - default-source-network-interface: the local network interface from where the
57 ping packages will originate. If this configuration is present, all hosts
58 will use this interface as source, otherwise, a per host source-network-
59 interface must be provided.
60 - nameserver: the server which the hosts names will be resolved. It is the
61 lookup server which the application will query first. If left blank or omited,
62 it will use the /etc/resolv.conf.
63 You can use the nslookup <host> to figure out the nameserver.
64 - hosts-down-limit: an absolute number, which ranges from 0 to the number of
65 hosts available. This value represents the minimum number of hosts that have
66 to fail (i.e. do not reply to the ping) in order to alert any external system.
67 - ping-fail-limit: percentage of pings to a host that can fail. If the
68 percentage of failed pings to a host exceed this number, then the host is
70 - status-notifier-cmd: the command line that is called when a host is down, or
71 up. Accepted variables are:
72 ${status} - down or up
73 - link-up-interval: how long (in minutes) the pings must be returned with
74 success in order to consider the link up, or stable.
75 - link-down-interval: how long (in minutes) the pings must fail, in order to the
76 application consider the link down.
80 ---------------------------------------
81 - name: the DNS or IP of the host to ping. Take in consideration that, if a
82 DNS is given, the application pings all IPs in the look up table, however, if
83 IP is provide, it is the only which will be pinged.
84 - port: when using a port based protocol, like TCP, this field specifies in
85 which port to ping the host.
86 - source-network-interface: the local network interface from where the ping
87 packages for a given host will originate. This setting is used only if the
88 global network interface was not provided.
89 - interval: the host will be pinged every "interval" seconds.
90 - ping-protocol: indicates which protocol to use to ping the destination host,
91 the currently supported protocols are TCP and ICMP.
96 =======================================
97 The command line accepts the general configuration file options plus the
99 - config-file: command line to specify a file where the hosts and other
100 configuration information are provided.
101 - daemon: run the application as a daemon.
102 - log-level: apply a filter of which log messages will be printed. The available
103 options are the default Unix levels (e.g. debug, info, etc.).
108 =======================================
109 [1] http://tools.ietf.org/html/rfc792
110 [2] http://en.wikipedia.org/wiki/Ping
111 [3] http://en.wikipedia.org/wiki/Internet_Control_Message_Protocol
112 [4] http://www.boost.org/doc/libs/1_45_0/doc/html/boost_asio.html
113 [5] http://www.boost.org/doc/libs/1_45_0/doc/html/program_options.html
114 [6] http://www.networkuptime.com/nmap/page4-4.shtml