Topology resolution overview
Adding devices to the topology tree
Adding devices automatically
Run Discover task by clicking on the circular arrow button below the AirControl2 logo at the top-left corner of the window.
If "Resolve topology" option is checked, the task will try to resolve topological relations among discovered devices. To do that it will need to login into each discovered device and extract network information by executing commands on it via SSH. User will be prompted to enter credentials for all the devices.
In the task window user can choose from which device in the topology discovery/resolution needs to be started. If "Topology Root" is chosen, discovery/resolution start from AC2 server by sending Layer-2 device-discovery broadcasts.
If discovery/resolution is started from a specific device in topology, the task will login into the device and execute discovery on that device via SSH 'discover' command. This approach is useful for discovering devices residing on subnets different from the ones that AC2 server running on.
Adding devices manually
If a device is not reachable through Layer-2 discovery, operator needs to add it manually by invoking context menu (using "right-click") on a "Topology root" or any device inside the topology tree and selecting "Add device manually" command. In the displayed add-device task panel operator needs to specify:
IP address of the device (DNS-name resolution currently not supported)
SSH port and SSH credentials
Membership type
Membership type defines how device discovery and topology resolution is performed with respect to this device. There are following types:
"Regular subnet member" - device resides on the same local subnet with respect to it's parent node
"Gateway to subnet" - device is on a different subnet with respect to it's parent. It is used as a "gateway" for discovering devices on it's subnet, as mentioned above the "discover" shell command will be executed by AC2 on the gateway device .
"NAT Gateway to Subnet" - similar to the "Gateway to subnet", such device is used as a gateway for discovering devices downstream of it. Additionally SSH tunnels are created on this device in order to reach/control the devices downstream of it, since those reside behind NAT. The NAT gateway device however needs to be accessible via specified IP/SSH-port combination from AC2 server directly.
IP-Range scan (or the lack of it)
Since AC2 possesses complete topology information, scanning IP ranges to discover devices normally becomes redundant (as opposed to AirControl 1.x). It is enough to add a Gateway or NAT-Gateway device manually and AC2 discovery/resolution task will gather all devices/topology information downstream of the gateway device automatically.
However, there are some cases when IP range-scan still has benefits: when adding a batch of devices/routers which are accessible via public IP and have large networks behind them. Range-scan task is on the road-map of AC2.
