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If only a single credential is available for a device (when using Credential Binding, or discovery Discovery with only a single credential added in the "Credentials" screen), Unimus will only open a single CLI session to the device after finding an available connector. Unimus will open connections to multiple devices at the same time (this can be configured as per the Changing maximum job concurrency article), but there will only be a single connection to each of these devices.
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- 1x TCP session to the device to check if SSH/Telnet is available (a TCP 3-way handshake will be performed and then the TCP session will be closed)
- 1x full CLI session will be negotiated (SSH/Telnet as configured by Connectors) and will be used to detect device vendor, model CLI modes, etc.
Please note this behavior applies to versions 2.2.0 and newer. Older Unimus versions will behave as described in the section below, even when only a single credential is available.
If multiple credentials are available for a device
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The discovery mechanism is what makes only the address of the device required when adding a new device into Unimus.
Unimus will automatically discovered discover everything else about the device.
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The discovery before backup is necessary to make sure Unimus doesn't user use wrong commands on the device.
In certain situations (ex. when a device is changed for another device) it's possible commands to generate backups on some vendors can actually cause configuration changes for other vendors.
Due to this (and other edge-cases) Unimus does a discovery before every backup.
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