LANMON was built for one single purpose. It's function is to monitor a list of nodes on your LAN and send an email alert if a node drops off the network. Its a very simple solution to a bigger SNMP application.
It requires zero install on the nodes being monitored. They only need to be able to respond to an ICMP ping.
LANMON needs to be running on a system that can send mail and implements a standard Linux mail command. The simplest way to test this is to execute the command: ' echo "TEST" | mail -s "Test email" ' where the emailaddress is, of course, your mail address. If this results in your receiving an email then you are good to go.
LAN runs off a standard JSON or TOML configuration file. The default file is ./lanmon.json and is of the form:
{
"alert_mins" : 1,
"alert" : "<<EMAIL-ADDRESS>",
"emailonrestore" : true,
"nodes" : [
"192.168.1.10" ,
"192.168.1.74",
"192.168.1.76",
"10.56.75.171",
"node1",
"node2",
"node3",
"2001:0db8:0000:0042:0000:8a2e:0370:7334"
]
}
the equivalent in TOML is
alert_mins = 1
alert = "myemail@domain.com"
emailonrestore = true
nodes = [
"192.168.1.10" ,
"192.168.1.74",
"192.168.1.76",
"10.56.75.171",
"o1",
"o2",
"o3"
]
where:
- alert_mins is the number of minutes a node needs to be offline before an alert will be generated. This is an integer positive number.
- alert is the emain address to receive alerts
- emailonrestore is a boolean where valid entries are either true or false. If set to true an email will be generated when the mode is restored to the network.
- nodes is a list of character strings representing the nodes to be monitored. This will accept nodes in three formats: IPV4; IPV6 or node name. The node will be checked on program startup to determine if an IP Address can be determined. It does not have to be active on startup, but it must be resolvable.
There should be no practical limit to the number of nodes available.
The nodes DO NOT have to be on the same subnet. Any node name can be monitored provided it responds to a ping.
LanMon is started as a background task. It does have a few command line flags.
Lan Monitor
Very simple LAN Monitor
USAGE:
lanmon [FLAGS] [OPTIONS]
FLAGS:
-h, --help Prints help information
-V, --version Prints version information
-v, --verbose Sets the level of verbosity
OPTIONS:
-c, --config <FILE> The JSON formatted config file [default: ./lanmon.json]
By default, only limited information messages are printed to the standard output file, stdout. This can be increased to include debug messages (-v) or trace messages (-vv).
NOTE ICMP Ping is treated as a privileged command. The lanmon executable needs to be either installed with setcap pribilege, or used as a sudo command.
LANMON is made available as source code only. This is because it executes with SUDO privileges, a requirement of the ICMP Ping protocol on Linux. No right minded sysadmin who wishes to monitor their network would accept an unsigned executable running in privilege mode. Hence LANMON needs to be compiled before being used.
LANMON is written in the rust programming language, so Rust and it's package manager, Cargo, must be installed prior to use. To check if Rust is installed, issue the commands seen below. you see output such as this, your good to go:
$ rustc -V
rustc 1.32.0-nightly (6acbb5b65 2018-11-25)
$ cargo -V
cargo 1.32.0-nightly (b3d0b2e54 2018-11-15)
$
To build LanMon issue the commands ''' github clone https://github.com/AdrianChallinorOsiris/lanmon.git cd lanmon cargo install --path . sudo setcap cap_net_raw+ep ~/.cargo/bin/lanmon '''
LanMon is licenses un the GNU General Public License v3.0 GPL 3
The Software is made available to you free of charge.
You may be entitled to warranties, conditions and terms that may not be excluded or limited by Osiris under law.
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