Auxillary NIC uses on the Datto (Legacy Hardware Platforms shown)


1. Scope

This article discusses the secondary NICs on Datto devices and their possible uses. Many of these pictures refer to the legacy hardware of Datto devices and may not reflect the newest hardware configurations.

Datto SIRIS appliances no longer require eth0 to hold the primary NIC assignment. You can use any NIC on a SIRIS as eth0.

2. Total Number of NICs by Datto Device Model

 Datto Siris / Siris Lite

Model:  S250   S500   S1000   S2000   S3000   S5000   S10000   S20000   S40000 
# of NICs:  2 2 2 2 4 4 4 4 4

Datto Viridian

Model:  V250   V500   V1000   V3000   V5000 
# of NICs: 2 3 3 4 4

 Datto G-Series

Model: G250   G500   GR500   G1000   G2000   G3000   G5000  
# of NICs: 1 1 1 1 3 3 4

2.1. Identifying Device NICs


Example: Datto Tower Case (See Legend below)


Example: Datto 2U Rackmount Case (See Legend below)


 Example: Datto 3U Case (See Legend below)


  1. AC Power Connection 110/220V
  2. Video Out (VGA/DVI)
  3. USB 2.0
  4. eth0
  5. eth1
  6. eth3 & eth4

3. Useful notes concerning auxiliary NICs

  • The top left corner of the Network tab on the Datto device's local web console reports if a cable is plugged in and report the link speed (100MB/1000MB)
  • Only plug NIC(s) in that are intended to be used. Don't enable NICs with no network attached. A configured but disconnected NIC may result in routing and name resolution issues

4. Possible operations for auxiliary NICs

4.1. NIC Bonding

  • If you have a supported Datto device, you can enable NIC bonding which will allow significantly improved backup and offsite sync performance.

4.2. Protection of machines on a separate subnet

  • If a Datto device needs to communicate across multiple subnets to protect various machines it may be configured to do so with the use of the auxiliary NICs as in some situations this configuration may be easier to set up than configuring a static route.
  • In these situations simply plug in a live network cable from the other subnet into one of the auxiliary NICs on the Datto.
  • Then configure the NIC on the Datto device's local web console under the Network tab for an IP and Netmask.

The gateway for the second NIC should be left as The Siris will lock out the gateway settings for the device.


Example: Datto device configured for protection of machines on Class A, B, & C subnets

4.3. Siris with ShadowSnap Network BMR

  • The Network Bare Metal Restore (BMR) process for Datto Siris with ShadowSnap devices use an auxiliary NIC to perform.  This however can be circumvented by use of a USB flash drive.
  • Please reference the Siris Bare Metal Restore Guide for further details.

4.4. Use separate NICs for Virtual Machines hosted on the Datto

  • By default a Virtual Machine launched on a Datto device (with network connectivity) will bridge to the primary NIC (eth0) for network connectivity and will not use the auxiliary NICs.
  • The auxiliary NIC(s) may however be used In some rare situations such as a Disaster-Recovery Virtual Machine of a Protected System in which multiple NICs are used in it's production environment.
  • The secondary NIC needs to have an address that can be made visible on the network and is not in use by any other machine.
    • It cannot be the IP address of the server that you are planning to utilize, it will need to be a separate address.

Datto Technical Support will need to assist with the configuration of virtualization software on the local device to use the auxiliary NICs.

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