NetworkTypes
SwitchSwitches are the default way to connect multiple elements. In contrast to direct connections, switches can connect more than two elements. Also switches can be stopped and reconnected without the need to stop all other connected elements.
Switches internally use the Tinc peer-to-peer VPN to connect the elements. Being a peer-to-peer network, the switch will not have a central bottleneck that all traffic must pass through.
Switches provide layer-2 connectivity to the connected elements regardless of the physical connections between the nodes hosting those elements.
The VPN is built below the operating system of the virtual machines so no additional software or configuration on the VMs is needed.
Normally the switch will learn MAC addresses and forward packets directly to the correct destination, only broadcasting to unknown destinations. This behavior can be disabled (and the switch be downgraded to a simple non-learnig hub) by changing the mode attribute to "hub".
External networksExternal networks are bridges into the outer world and the only way elements inside the topology can communicate with the outside.
Different external networks can be chosen, each with a unique environment that is detailed in the description of the external network. In general, users can assume that addresses in external networks are assigned using DHCP on a first-come-first-serve basis.
ToMaTo can bridge elements to external networks on remote hosts using tunnels that are automatically built as needed.
Note: If external networks are connected directly or with forwarding nodes in between it is possible to build a network loop. The editor will do its best to detect this and warn the user but users should still be careful.