ToMaTo - Topology Management Tool

ToMaTo

Origin

ToMaTo is being developed as part of the experimental facility of the German-Lab project
Open-Source since version 2.0

What it is

A topology-oriented testbed software
An easy-to-use feature-rich tool for networking experiments

What it is NOT

A management tool for physical network topologies — Topologies are virtual
A tool to manage virtualized production networks — ToMaTo is still under development
A virtualization solution or virtualization frontend — ToMaTo is more

Topology elements

ToMaTo is topology-oriented, i.e. users build topologies for their experiments.

Devices

produce and consume data
can run software

Connectors

forward and manipulate data
connect devices

Three kinds of devices

KVM devices
OpenVZ devices
Programmable devices

Two kinds of connectors

VPN networks
External networks

KVM devices

Full virtualization (KVM)

Emulated hardware
Nearly all x86 operating systems supported

Pros

KVM devices can run any x86 operating system

Windows
Linux
BSD

Linux inside KVM can run custom kernels

Cons

KVM virtual machines use lots of resources
Access to the VM is complicated

Login needed
VM is hard to control with scripts

Interfaces cannot be configured by ToMaTo

OpenVZ devices

Container virtualization (OpenVZ)

Guest operating systems share the Linux kernel of the host system
Only userspace (users, files, processes, etc.) is virtualized
Restricted access to kernel-space (hardware, filesystems, kernel modules, kernel variables, etc.)
Nearly all Linux distributions can be run

Pros

OpenVZ can run nearly any Linux operating system
Easy to access remotely

Completely scriptable

Efficient resource usage
Network interfaces fully configurable

also using the ToMaTo editor

Cons

Only Linux systems
Limited kernel space access

No kernel modules
Restricted access to some kernel calls

Programmable devices

Sandboxed python scripts (Repy)

Raw network packets can be processed with python scripts
Sandboxing environment disallows some language elements (also most python libraries)
ToMaTo contains library of network protocols and server implementations

Pros

Very lightweight, uses nearly no resources
Completely free to define packet processing
Extensive library ready to use
Parameters can be defined by ToMaTo

Cons

Cannot run any standard software
Most python libraries not available

Device features

Console access

Direct access to device console from webfrontend
Remote control of the device via mouse and keyboard (only OpenVZ and KVM)
Optional access via VNC (RFB protocol) using standard clients

Image upload/download

Download and upload the virtual harddisk of the device
Exchange the script of a programmable device
Can be used for backups or to clone an existing device
VMs can be imported into ToMaTo

Device templates

Pre-installed standard operating systems

Various Linux distributions: Debian, Ubuntu, ...
Windows (only KVM, not public due to legal restrictions)
FreeBSD (only KVM)

Lots of programmable device scripts: DNS server, DHCP server, Pingable node, ...
Templates can be managed by admins

Connectors

Connectors forward and manipulate networking packets on their way between devices.

VPN networks

Based on Tinc peer-to-peer VPN
Configurable semantics: Hub, Switch or Router (needs additional configuration)
Network is a virtual ethernet segment (not with router semantics)
Network is completely contained, no packets enter, no packets escape
VPN can work between different sites
Users can enter the VPN using VTun

External networks

Connect devices to an external network, accessible on the host system
Defined openings in the experiment topology
Mosty used for Internet connections
Experimental research networks can be accessed
Can be used to include other resources into the topology (like Planet-Lab slices)

Connecting with devices

Devices can be used instead of connectors to provide special forwarding or manipulation schemes. Programmable devices offer an easy way to implement complex forwarding and packet manipulation algorithms.

VPN connector extra features

Link emulation

Add delay to connections, configurable jitter, stochastic distributions
Add packet loss to connections, optionally correlated
Add packet dulpication and corruption, optionally correlated
Bandwidth limits down to a few kb/sec
All attributes can be configured on both directions individually

Packet capturing

Capture packets on connections with full tcpdump filter support
Captured packets can be downloaded in standard pcap format

Can be opened in packet analysis tools like Wireshark
Can be uploaded and analyzed in Cloudshark (integrated in ToMaTo webfrontend)

Live-capturing feature sends packets directly to a running Wireshark instance

Topology editor

Editor usage

Elements can be added from the palette on the right using drag&drop
Lots of attributes can be edited in the attribute panels
Topology settings can be changed using the topology icon

Editor features

Interface auto-configuration
Automatic creation of huge topologies
Topology usage directly from editor

ToMaTo structure

Facility hosts

Running Proxmox VE + additional software
No need for layer 2 connectivity
Organized in sites

Backend component

Central component for orchestration
Controls hosts via SSH
User management via authentication plugins
Provides XML-RPC interface

Multiple frontends

Web-based, Command-line, Automated scripts, ...
Use common XML-RPC interface
More frontends possible

Obtaining and contributing

How to get ToMaTo

ToMaTo is Open-Source! It can be simply downloaded from the Github page. There is also a step-by-step tutorial on how to setup ToMaTo in a testbed. ToMaTo includes some nice features that make it pretty easy to install it in an experimental facility:

All components packaged for debian (updates come automatically)
Multiple authentication plugins: LDAP, htaccess, SQL-Database, Planet-Lab, ...
Automatic checks and problem reports for the ToMaTo hosts

How to contribute to ToMaTo

As an Open-Source project ToMaTo is open for hints and contributions.

Github offers an easy way to fork the project and offer contributions as pull requests
The wiki is publically editable so everyone can help by adding to the documentation
The issue tracking system can be used for bug reports and feature requests