- How do I install LibreNMS?
- How do I add a device?
- How do I get help?
- What are the supported OSes for installing LibreNMS on?
- Do you have a demo available?
- How does LibreNMS use MIBs?
- Why do I get blank pages sometimes in the WebUI?
- Why do I not see any graphs?
- How do I debug pages not loading correctly?
- How do I debug the discovery process?
- How do I debug the poller process?
- Why do I get a lot apache or rrdtool zombies in my process list?
- Why do I see traffic spikes in my graphs?
- Why do I see gaps in my graphs?
- How do I change the IP / hostname of a device?
- My device doesn't finish polling within 300 seconds
- Things aren't working correctly?
- What do the values mean in my graphs?
- Why does a device show as a warning?
- Why do I not see all interfaces in the Overall traffic graph for a device?
- How do I move my LibreNMS install to another server?
- Why is my EdgeRouter device not detected?
- Why are some of my disks not showing?
- Why are my disks reporting an incorrect size?
- What does mean \"ignore alert tag\" on device, component, service and port?
- Why can't Normal and Global View users see Oxidized?
- What is the Demo User for?
- Why does modifying 'Default Alert Template' fail?
- Why would alert un-mute itself
- How do I change the Device Type?
- Where do I update my database credentials?
- My reverse proxy is not working
- My alerts aren't being delivered on time
- My alert templates stopped working
- How do I use trend prediction in graphs
- How do I add support for a new OS?
- What information do you need to add a new OS?
- What can I do to help?
- How can I test another users branch?
This is currently well documented within the doc folder of the installation files.
Please see the following doc
You have two options for adding a new device into LibreNMS.
1: Using the command line via ssh you can add a new device by changing to the directory of your LibreNMS install and typing (be sure to put the correct details).
./addhost.php [community] [v1|v2c] [port] [udp|udp6|tcp|tcp6]
Please note that if the community contains special characters such as
$then you will need to wrap it in
2: Using the web interface, go to Devices and then Add Device. Enter the details required for the device that you want to add and then click 'Add Host'.
Supported is quite a strong word :) The 'officially' supported distros are:
- Ubuntu / Debian
- Red Hat / CentOS
However we will always aim to help wherever possible so if you are running a distro that isn't one of the above then give it a try anyway and if you need help then jump on the discord server.
We do indeed, you can find access to the demo here
LibreNMS does not parse MIBs to discover sensors for devices. LibreNMS uses static discovery definitions written in YAML or PHP. Therefore, updating a MIB alone will not improve OS support, the definitions must be updated. LibreNMS only uses MIBs to make OIDs easier to read.
You can enable debug information by setting
APP_DEBUG=true in your
.env. (Do not leave this enabled, it could leak private data)
If the page you are trying to load has a substantial amount of data in it then it could be that the php memory limit needs to be increased in config.php.
The easiest way to check if all is well is to run
root from within your install directory. This should give you info on
why things aren't working.
One other reason could be a restricted snmpd.conf file or snmp view which limits the data sent back. If you use net-snmp then we suggest using the included snmpd.conf file.
A debug system is in place which enables you to see the output from php errors, warnings and notices along with the MySQL queries that have been run for that page.
You can enable debug information by setting
APP_DEBUG=true in your
.env. (Do not leave this enabled, it could leak private data) To see
additional information, run
to install additional debug tools. This will add a debug bar at the
bottom of every page that will show you detailed debug information.
Please see the Discovery Support document for further details.
Please see the Poller Support document for further details.
If this is related to your web service for LibreNMS then this has been tracked down to an issue within php which the developers aren't fixing. We have implemented a work around which means you shouldn't be seeing this. If you are, please report this in issue 443.
This occurs either when a counter resets or the device sends back bogus data making it look like a counter reset. We have enabled support for setting a maximum value for rrd files for ports.
Before this all rrd files were set to 100G max values, now you can enable support to limit this to the actual port speed.
rrdtool tune will change the max value when the interface speed is detected as being changed (min value will be set for anything 10M or over) or when you run the included script (./scripts/tune_port.php) - see RRDTune doc
SNMP ifInOctets and ifOutOctets are counters, which means they start at 0 (at device boot) and count up from there. LibreNMS records the value every 5 minutes and uses the difference between the previous value and the current value to calculate rate. (Also, this value resets to 0 when it hits the max value)
Now, when the value is not recorded for awhile RRD (our time series storage) does not record a 0, it records the last value, otherwise, there would be even worse problems. Then finally we get the current ifIn/OutOctets value and record that. Now, it appears as though all of the traffic since it stopped getting values have occurred in the last 5 minute interval.
So whenever you see spikes like this, it means we have not received data from the device for several polling intervals. The cause can vary quite a bit: bad snmp implementations, intermittant network connectivity, broken poller, and more.
This is most commonly due to the poller not being able to complete it's run within 300 seconds. Check which devices are causing this by going to /poll-log/ within the Web interface.
When you find the device(s) which are taking the longest you can then look at the Polling module graph under Graphs -> Poller -> Poller Modules Performance. Take a look at what modules are taking the longest and disabled un used modules.
If you poll a large number of devices / ports then it's recommended to run a local recurisve dns server such as pdns-recursor.
Running RRDCached is also highly advised in larger installs but has benefits no matter the size.
There is a host rename tool called renamehost.php in your librenms root directory. When renaming you are also changing the device's IP / hostname address for monitoring.
./renamehost.php <old hostname> <new hostname>
You can also rename a device in the Web UI by going to the device, then clicking settings Icon -> Edit.
We have a few things you can try:
- Disable unnecessary polling modules under edit device.
- Set a max repeater value within the snmp settings for a device. What to set this to is tricky, you really should run an snmpbulkwalk with -Cr10 through -Cr50 to see what works best. 50 is usually a good choice if the device can cope.
./validate.php as root from within your install.
./validate.php once you've resolved any issues raised.
You have an odd issue - we'd suggest you join our discord server to discuss.
The values you see are reported as metric values. Thanks to a post on Reddit here are those values:
10^-18 a - atto 10^-15 f - femto 10^-12 p - pico 10^-9 n - nano 10^-6 u - micro 10^-3 m - milli 0 (no unit) 10^3 k - kilo 10^6 M - mega 10^9 G - giga 10^12 T - tera 10^15 P - peta
This is indicating that the device has rebooted within the last 24
hours (by default). If you want to adjust this threshold then you can
do so by setting
$config['uptime_warning'] = '84600'; in
config.php. The value must be in seconds.
By default numerous interface types and interface descriptions are excluded from this graph. The excluded defailts are:
$config['device_traffic_iftype'] = '/loopback/'; $config['device_traffic_iftype'] = '/tunnel/'; $config['device_traffic_iftype'] = '/virtual/'; $config['device_traffic_iftype'] = '/mpls/'; $config['device_traffic_iftype'] = '/ieee8023adLag/'; $config['device_traffic_iftype'] = '/l2vlan/'; $config['device_traffic_iftype'] = '/ppp/'; $config['device_traffic_descr'] = '/loopback/'; $config['device_traffic_descr'] = '/vlan/'; $config['device_traffic_descr'] = '/tunnel/'; $config['device_traffic_descr'] = '/bond/'; $config['device_traffic_descr'] = '/null/'; $config['device_traffic_descr'] = '/dummy/';
If you would like to re-include l2vlan interfaces for instance, you
first need to
unset the config array and set your options:
unset($config['device_traffic_iftype']); $config['device_traffic_iftype'] = '/loopback/'; $config['device_traffic_iftype'] = '/tunnel/'; $config['device_traffic_iftype'] = '/virtual/'; $config['device_traffic_iftype'] = '/mpls/'; $config['device_traffic_iftype'] = '/ieee8023adLag/'; $config['device_traffic_iftype'] = '/ppp/';
If you are moving from one CPU architecture to another then you will need to dump the rrd files and re-create them. If you are in this scenario then you can use Dan Brown's migration scripts.
If you are just moving to another server with the same CPU architecture then the following steps should be all that's needed:
- Install LibreNMS as per our normal documentation; you don't need to run through the web installer or building the sql schema.
- Stop cron by commenting out all lines in
- Dump the MySQL database
librenmsfrom your old server (
mysqldump librenms -u root -p > librenms.sql)...
- and import it into your new server (
mysql -u root -p < librenms.sql).
- Copy the
rrd/folder to the new server.
- Copy the
config.phpfile to the new server.
- Check for modified files (eg specific os, ...) with
git statusand migrate them.
- Ensure ownership of the copied files and folders (substitute your
user if necessary) -
chown -R librenms:librenms rrd/; chown librenms:librenms config.php
- Delete old pollers on the GUI (gear icon --> Pollers --> Pollers)
- Validate your installation (/opt/librenms/validate.php)
- Re-enable cron by uncommenting all lines in
If you have
service snmp description set in your config then this
will be why, please remove this. For some reason Ubnt have decided
setting this value should override the sysDescr value returned which
breaks our detection.
If you don't have that set then this may be then due to an update of EdgeOS or a new device type, please create an issue.
If you are monitoring a linux server then net-snmp doesn't always
expose all disks via hrStorage (HOST-RESOURCES-MIB). We have
additional support which will retrieve disks via dskTable
(UCD-SNMP-MIB). To expose these disks you need to add additional
config to your snmpd.conf file. For example, to expose
which may be mounted as
/storage you can specify:
Restart snmpd and LibreNMS should populate the additional disk after a fresh discovery.
There is a known issue for net-snmp, which causes it to report incorrect disk size and disk usage when the size of the disk (or raid) are larger then 16TB, a workaround has been implemented but is not active on Centos 6.8 by default due to the fact that this workaround breaks official SNMP specs, and as such could cause unexpected behaviour in other SNMP tools. You can activate the workaround by adding to /etc/snmp/snmpd.conf :
Tag device, component, service and port to ignore alerts. Alert checks will still run.
However, ignore tag can be read in alert rules. For example on device, if
devices.ignore = 0
macros.device = 1 condition is is set and ignore alert tag is on,
the alert rule won't match. The alert rule is ignored.
Please see Supporting a new OS if you are adding all the support yourself, i.e. writing all of the supporting code. If you are only able to supply supporting info, and would like the help of others to write up the code, please follow the below steps.
Under the device, click the gear and select Capture.
You can also use the command line to obtain the information.
Especially, if snmpwalk results in a large amount of data. Replace the
relevant information in these commands such as HOSTNAME and
snmpwalk instead of
snmpbulkwalk for v1 devices.
These commands will automatically upload the data to LibreNMS servers.
./discovery.php -h HOSTNAME -d | ./pbin.sh ./poller.php -h HOSTNAME -r -f -d | ./pbin.sh snmpbulkwalk -OUneb -v2c -c COMMUNITY HOSTNAME . | ./pbin.sh
You can use the links provided by these commands within the issue.
If possible please also provide what the OS name should be if it doesn't exist already.
Thanks for asking, sometimes it's not quite so obvious and everyone can contribute something different. So here are some ways you can help LibreNMS improve.
- Code. This is a big thing. We want this community to grow by the software developing and evolving to cater for users needs. The biggest area that people can help make this happen is by providing code support. This doesn't necessarily mean contributing code for discovering a new device:
- Web UI, a new look and feel has been adopted but we are not finished by any stretch of the imagination. Make suggestions, find and fix bugs, update the design / layout.
- Poller / Discovery code. Improving it (we think a lot can be done to speed things up), adding new device support and updating old ones.
- The LibreNMS main website, this is hosted on GitHub like the main repo and we accept use contributions here as well :)
- Hardware. We don't physically need it but if we are to add device support, it's made a whole lot easier with access to the kit via SNMP.
- If you've got MIBs, they are handy as well :)
- If you know the vendor and can get permission to use logos that's also great.
- Bugs. Found one? We want to know about it. Most bugs are fixed after being spotted and reported by someone, I'd love to say we are amazing developers and will fix all bugs before you spot them but that's just not true.
- Feature requests. Can't code / won't code. No worries, chuck a feature request into our community forum with enough detail and someone will take a look. A lot of the time this might be what interests someone, they need the same feature or they just have time. Please be patient, everyone who contributes does so in their own time.
- Documentation. Documentation can always be improved and every little bit helps. Not all features are currently documented or documented well, there's speeling mistakes etc. It's very easy to submit updates through the GitHub website, no git experience needed.
- Be nice, this is the foundation of this project. We expect everyone to be nice. People will fall out, people will disagree but please do it so in a respectable way.
- Ask questions. Sometimes just by asking questions you prompt deeper conversations that can lead us to somewhere amazing so please never be afraid to ask a question.
LibreNMS can and is developed by anyone, this means someone may be working on a new feature or support for a device that you want. It can be helpful for others to test these new features, using Git, this is made easy.
Firstly ensure that your current branch is in good state:
If you see
nothing to commit, working directory clean then let's go for it :)
Let's say that you want to test a users (f0o) new development branch (issue-1337) then you can do the following:
git remote add f0o https://github.com/f0o/librenms.git git remote update f0o git checkout issue-1337
Once you are done testing, you can easily switch back to the master branch:
git checkout master
If you want to pull any new updates provided by f0o's branch then whilst you are still in it, do the following:
git pull f0o issue-1337
Configs can often contain sensitive data. Because of that only global admins can see configs.
Demo users allow full access except adding/editing users and deleting devices and can't change passwords.
This template's entry could be missing in the database. Please run this from the LibreNMS directory:
php artisan db:seed --class=DefaultAlertTemplateSeeder
If alert un-mutes itself then it most likely means that the alert cleared and is then triggered again. Please review eventlog as it will tell you in there.
You can change the Device Type by going to the device you would like to change, then click on the Gear Icon -> Edit. If you would like to define custom types, we suggest using Device Groups. They will be listed in the menu similarly to device types.
If you've changed your database credentials then you will need to
update LibreNMS with those new details.
Please edit both
$config['db_host'] = ''; $config['db_user'] = ''; $config['db_pass'] = ''; $config['db_name'] = '';
DB_HOST= DB_DATABASE= DB_USERNAME= DB_PASSWORD= DB_PORT=
Make sure your proxy is passing the proper variables. At a minimum: X-Forwarded-For and X-Forwarded-Proto (X-Forwarded-Port if needed)
You also need to Set the proxy or proxies as trusted
If you are using a subdirectory on the reverse proxy and not on the actual web server,
you may need to set APP_URL and
If you're running MySQL/MariaDB on a separate machine or container make sure the timezone is set properly on both the LibreNMS and MySQL/MariaDB instance. Alerts will be delivered according to MySQL/MariaDB's time, so a mismatch between the two can cause alerts to be delivered late if LibreNMS is on a timezone later than MySQL/MariaDB.
You should probably have a look in the documentation concerning the new template syntax: https://docs.librenms.org/Alerting/Templates/. Since version 1.42, syntax changed, and you basically need to convert your templates to this new syntax (including the titles).
As of Ver. 1.55 a new feature has been added where you can view a simple linear prediction in port graphs.
It doesn't work on non-port graphs or consolidated graphs at the time this FAQ entry was written.
To view a prediction:
- Click on any
portgraph of any network device
- Select a
Fromdate to your liking (not earlier than the device was actually added to LNMS), and then select a future date in the
- Click update
You should now see a linear prediction line on the graph.