Title: Monitor your remote host network quality using smokeping on
OpenBSD
Author: Solène
Date: 26 March 2023
Tags: nocloud openbsd networking
Description: In this article you will learn how to install and setup
Smokeping on OpenBSD in order to monitor the network quality of remote
hosts.
# Introduction
If you need to more the network quality of a link, or the network
availability of a remote host, I'd recommend you to take a look at
Smokeping.
(HTM) Smokeping official Website
Smokeping is a Perl daemon that will regularly run a command (fping,
some dns check, etc…) multiple times to check the availability of the
remote host, but also the quality of the link, including the standard
deviation of the response time.
It becomes very easy to know if a remote host is flaky, or if the link
where Smokeping runs isn't stable any more when you see that all the
remote hosts have connectivity issues.
Let me explain how to install and configure it on OpenBSD 7.2 and 7.3.
# Installation
Smokeping comes in two parts, but they are in the same package, the
daemon components to run it 24/7 to gather metrics, and the fcgi
component used to render the website for visualizing data.
First step is to install the `smokeping` package.
```shell
# pkg_add smokeping
```
The package will also install the file
`/usr/local/share/doc/pkg-readmes/smokeping` giving explanations for
the setup. It contains a lot of instructions, from the setup to
advanced configuration, but without many explanations if you are new to
smokeping.
## The daemon
Once you installed the package, the first step is to configure
smokeping by editing the file `/etc/smokeping/config` as root.
Under the `*** General ***` section, you can change the variables
`owner` and `contact`, this information is displayed on Smokeping HTML
interface, so if you are in company and some colleague look at the
graphs, they can find out who to reach if there is an issue with
smokeping or with the links. This is not useful if you use it for
yourself.
Under the `*** Alerts ***` section, you can configure the emails
notifications by configuring `to` and `from` to match your email
address, and a custom address for smokeping emails origin.
Then, under `*** Targets ***` section, you can configure each host to
monitor. The syntax is unusual though.
* lines starting with `+ SomeSingleWord` will create a category with
attributes and subcategories. Attribute `title` is used to give a name
to it when showing the category, and `menu` is the name displayed on
the sidebar on the website.
* lines starting with `++ SomeSingleWord` will create a subcategory for
a host. Attributes `title` and `menu` works the same as the first
level, and `host` is used to define the remote host to monitor, it can
be a hostname or an IP address.
That's for the simplest configuration file. It's possible to add new
probes such as "SSH Ping", DNS, Telnet or LDAP...
Let me show a simple example of targets configuration I'm using:
```smokeping
*** Targets ***
probe = FPing
menu = Top
title = Network Latency Grapher
remark = Welcome to the SmokePing
+ Remote
menu= Remote
title= Remote hosts
++ Persopw
menu = perso.pw
title = My server perso.pw
host = perso.pw
++ openportspl
menu = openports.pl
title = openports.pl VM at openbsd.amsterdam
host = openports.pl
++ grifonfr
menu = grifon.fr
title = grifon.fr VPN endpoint
host = 89.234.186.37
+ LAN
menu = Lan
title = Lan network at home
++ solaredge
menu = solaredge
title = solardedge
host = 10.42.42.246
++ modem
menu = ispmodem
title = ispmodem
host = 192.168.1.254
```
Now you configured smokeping, you need to enable the service and run
it.
```shell
# rcctl enable smokeping
# rcctl start smokeping
```
If everything is alright, `rcctl check smokeping` shouldn't fail, if
so, you can read `/var/log/messages` to find why it's failing.
Usually, it's a `+` line that isn't valid because of a non-authorized
character or a space.
I recommend to always add a public host of a big platform that is known
to be working reliably all the time, to have a comparison point against
all your other hosts.
## The Web Interface
Now the daemon is running, you certainly want to view the graphs
produced by Smokeping. Reusing the example from the pkg-readme file,
you can configure httpd web server with this:
```httpd.conf
server "smokeping.example.org" {
listen on * port 80
location "/smokeping/smokeping.cgi*" {
fastcgi socket "/run/smokeping.sock"
root "/"
}
}
```
Your service will be available at the address
`http://smokeping.example.org/smokeping/smokeping.cgi`.
For this to work, we need to run a separate FCGI server, fortunately
packaged as an OpenBSD service.
```shell
# rcctl enable smokeping_fcgi
# rcctl start smokeping_fcgi
```
Note that there is a way to pre-render all the HTML interface by a cron
job, but I don't recommend it as it will drain a lot of CPU for
nothing, except if you have many users viewing the interface and that
they don't need interactive zoom on the graphs.
# Conclusion
Smokeping is very effective because of the way it renders data, you can
easily spot issues in your network that a simple ping or response time
wouldn't catch.
Please note it's better to have two smokeping setup at different places
in order to monitor each other remote smokeping link quality.
Otherwise, if a remote host appear flaky, you can't entirely be sure if
the Internet access of the smokeping is flaky, or if it's the remote
host, or a peering issue.
Here is the 10 days graph for a device I have on my LAN but connected
to the network using power line networking.
(IMG) Monitoring graph of a device connected on LAN using power line network
Don't forget to read `/usr/local/share/doc/pkg-readmes/smokeping` and
the official documentation if you want a more complicated setup.