Network Operations Centre (NOC)

The NOC is the simplest topology, and we recommend you start with this to get familiar with the platform.

Its purpose is to be able to demonstrate the Network Monitoring and Management tools to the class, populated with real data. It can become a long-term store of monitoring data collected over months and years, giving a more meaningful collection of data to show than the data the students themselves collect over a few days.

It's also helpful for you, the instructor, to practice configuring these tools.


NOC consists of a single virtual machine, ( It runs the same VM image as the NMM training course.

NOC topology

The NAT "cloud" represents the connection to the virbr0 bridge.

The GNS3 project configures the NOC VM to have 2.5GB RAM. It should be possible to run this project on a machine with as little as 4GB.


You will need the following files:

File Description
noc-<version>.gns3project the GNS3 project
nsrc-nmm-<version>.qcow2 the VM image with NMM tools pre-installed (large download: ~2GB)
noc-hdb-<version>.img the cloud-init image which configures username/password and static IP

Note that this topology does not use the Cisco IOSv or IOSvL2 images. This means that it is completely free to use, and can be freely shared.

IP addresses

IP Address DNS Name

Note that the NOC's IPv6 default gateway is the TR1/TR2 transit routers in the teaching topology. Hence if the teaching topology is down, IPv6 connectivity won't work.

This means that if you want to ssh from the server to the NOC VM, and the teaching topology is not running, you need to force IPv4:

ssh -4
# OR
ssh sysadm@


  • ssh login: sysadm and nsrc+ws (the standard student login). It's up to you whether you wish to keep this or change it. One the one hand, you might want students to be able to login and look around; on the other hand, you might want to protect it from being damaged by students.
  • nagios login: nagiosadmin and nsrc+ws
  • LibreNMS login:, admin and nsrc+ws
  • netbox login: admin and nsrc+ws
  • cacti login: admin and nsrc+ws. On older systems (based on Ubuntu 16.04) it is admin and admin; it then prompts for password change.
  • RT login: root and nsrc+ws
  • mysql root password: nsrc+ws
  • grafana initial login: admin and admin (but password change is forced)
  • VictoriaMetrics API: admin and password123


The NMM tools are in an unconfigured state, but there are some scripts you can run to perform a basic automated setup for the CNDO/NMM topology.

Login to the NOC, using SSH or at the console, and run the following commands:

git clone
cd nsrc-noc-setup

It's a good idea to reboot to ensure everything comes up as expected.


Some Grafana dashboards are imported. Use the magnifying glass (Search) icon to find them, or go to Dashboards > Manage > NOC Dashboards.

Alternatively, you may wish to configure them by hand, following the NMM lab exercises. You could:

  • Monitor the classroom hardware (access point, switch)
  • Monitor external resources (e.g. smokeping DNS test to
  • Monitor the labs, e.g. Nagios checks of bdr1 and core1 in each campus, so you can visualise how the class is progressing. Note that you won't be able to directly reach the dist and edge switches in CNDO, as they are behind NAT.
  • Collect configs from transit1-nren and transit2-nren ( and .3) using rancid
  • Generate graphs of classroom bandwidth usage - SNMP monitoring of in LibreNMS
  • Collect classroom netflow data in nfsen. This can be extremely interesting to see which students are running torrents!

You should also install a HTML page at /var/www/html/index.html which links to all the tools. You can use this sample as a base.


To allow your physical host to be monitored by LibreNMS, install and configure snmpd.


Do this on your physical host, not inside the NOC VM

sudo apt-get install snmpd

Refer to the snmp labs in the NMM workshop for how to configure an SNMPv2c community string and SNMPv3 authentication. Ensure that the ACL allows access from

Then return to the LibreNMS web interface and add "" as a device. It will take up to 5 minutes for it to be discovered.


To generate netflow data for traffic going in and out of the class, install softflowd on your server.


Do this on your physical host, not inside the NOC VM

sudo apt-get install softflowd

Edit /etc/default/softflowd


OPTIONS="-n -v 9 -t maxlife=5m"

Create /etc/systemd/system/softflowd.service


ExecStart=/usr/sbin/softflowd -d -i $INTERFACE $OPTIONS


Be careful to get uppercase and lowercase exactly correct.


Although softflowd comes with an init script, we replace it with a systemd service which auto-restarts it on failure. This is because on bootup, the system tries to start softflowd before libvirt has created the virbr0 interface.

Now start softflowd:

sudo systemctl daemon-reload
sudo systemctl start softflowd
sudo systemctl enable softflowd

Then, login to the NOC VM. You will need to start nfsen there, just like the students would have had to:


Do the following inside the NOC VM

sudo update-rc.d nfsen defaults 20
sudo service nfsen start

Data will become visible at


To allow the host to be monitored by prometheus, install node_exporter.

For the current version, follow the instructions in the lab exercise. An older version can be obtained via apt-get install prometheus-node-exporter.


Since the NOC is a separate topology, you can keep your NOC running even when you shutdown or wipe your teaching topologies. This is what allows it to continue to collect data over the long term.

To make this even more useful, you can arrange that:

  • The NOC project is opened automatically whenever the GNS3 server starts
  • The NOC VM is started automatically when the NOC project is opened
  • The NOC project continues running in the background even when you close the GNS3 client

These options are available under File > Edit Project in the GNS3 client.

GNS3 project options