CORE 7.5.2 / Vagrant VM - Multicast network testbed

Multicast test environment

CORE 7.5.2 [1] is the last of the supported Tcl-based CORE versions. It provides Quagga-based routing with protocols such as OSPF, RIP, BGP and OSPF-MDR.

Multicast isn't well supported out of the box in CORE, so this Vagrant setup adds support for PIM-DM using pimd-dense [2] and static multicast routing using smcroute [3]. A service wrapper script pimdm.py for PIM-DM and a service wrapper script smcroute.py for static multicast will be inserted at ~/.core/myservices. This file location is the usual place for custom CORE services.

A couple of helper scripts mcsend and mcrecv are included to generate mutlicast traffic and receive multicast traffic using iperf [4]. These are typically run from the commandline inside a simulated data terminal instance.

Example

Assuming a typical multicast scenario: DT1 <--> Rtr1 <--> Rtr2 <--DT2

Sender Example using multicast address 239.1.1.1:

DT1$ mcsend 239.1.1.1 

Receiver Example using multicast address 239.1.1.1:

DT2$ mcrecv 239.1.1.1

Public service reminders

• Everyone forgets at least once, but a multicast router requires 2 interfaces, so pimd-dense won't start if a router has only one interface.
• Also, OSPFv2 takes 40 seconds to set up a route and multicast needs a unicast route in place to begin forwarding. If multicast isn't working, just wait a bit or swap out OSPFv2 protocol to something faster like RIPv2.

Installation

Vagrant is used to create the Virtualbox VM for CORE, install the custom multicast services in CORE and build CORE, ospf-mdr, pimd-dense, and smcroute from source. The source tarballs will be downloaded during the installation.

Assumptions:

• you have some familiarity with VirtualBox and Vagrant.
• Virtualbox on Linux is installed (apt install virtualbox)
• vagrant is installed (apt install vagrant)

Install:

From a terminal:

 ./create_core_vm.sh

Installation takes about 5-10 minutes. You will be prompted at one point to enter the vagrant password -- it's "vagrant".

Post-install:

The VirtualBox GUI will be available during the install process, but not usable until after the installation has been completed. From the core752 directory on the HostMachine:

vagrant halt  # stops the running core752 VM
vagrant up    # starts the core752 VM (and GUI)
vagrant ssh   # ssh into the running core752 VM

## if disaster has struck, then the next line cleans everything up
vagrant destroy # you destroyed the core752 VM and need to re-run the install script

Validate:

HostMachine> Stop the VM: 'vagrant halt'

HostMachine> Start the VM: 'vagrant up'

VM GUI > Confirm that CORE runs - from a command line run 'core-gui'

VM GUI > Confirm that CORE daemon runs - from a command line run 'sudo service core-daemon status'. If not running, the 'sudo service core-daemon start'

Multicast in CORE

The pimdm.py service in CORE automatically adds router interfaces to its configuration file pimdm.conf. Right-clicking on a router icon and selecting the Services menu item brings up the set of available services including a Multicast section with both PIM-DM and SMCroute.

References:

[1] https://github.com/coreemu/core

[2] https://github.com/troglobit/pimd-dense

[3] https://github.com/troglobit/smcroute

[4] https://iperf.fr/