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Connect to an AnywhereUSB over the Internet


First, it's important to note that the host computer initiates the connection to the AnywhereUSB, not the other way around.

Typical AnywhereUSB installations are in LAN environments, e.g. where the host computer (the computer with the AnywhereUSB software) is on the same subnet as the AnywhereUSB and NAT (Network Address Translation) is not being used.  For example, the host computer might have an IP address of and the AnywhereUSB might have an IP address of  Connecting to an AnywhereUSB in this kind of scenario - when the host computer can ping the AnywhereUSB's IP address directly - is very simple.  Just select the AnywhereUSB in the AnywhereUSB Configuration Utility and click the Connect button.  Alternatively, you can "manually" add the AnywhereUSB's IP address to the "Connection List" in the AnywhereUSB Configuration Utility (via "Edit / Connection List"), which is ultimately what the Connect button does.

When a router or firewall exists between the host computer, however (e.g. when the "Internet cloud" is between the host computer and AnywhereUSB), the standard method to connect will not work, because there's no route from the host computer to the AnywhereUSB.  In other words, because the host computer cannot reach the AnywhereUSB's IP address, it's not possible to connect to the AnywhereUSB, at least without configuring the router/firewall appropriately.

This KB article aims to explain how to configure the router/firewall, host computer, and AnywhereUSB, so that the host computer can connect to the AnywhereUSB "over the Internet".  This information also applies to "connecting to an AnywhereUSB over a WAN" scenarios.


  • The AnywhereUSB is located "behind" a router or firewall, and the AnywhereUSB has a private IP address, e.g.
  • The AnywhereUSB's (IPv4) network settings must be configured properly, so the AnywhereUSB is able to access the Internet.  Having an improper default gateway IP address, or no gateway IP address, is a common cause of this type of scenario not working.
  • The host computer has Internet access, and a route to the router/firewall, e.g. it can ping the router/firewall (assuming that the router/firewall responds to pings).
  • NAT is enabled on the public-facing interface of the router/firewall.
  • Although it's not required, it's strongly suggested that both the AnywhereUSB and the router/firewall have Static IP addresses, otherwise settings changes WILL have to be made occasionally, if/when the IP address of the AnywhereUSB or router/firewall changes.  If it's not possible to assign a Static IP address to the AnywhereUSB's, consider using a DHCP Reservation AKA Static Lease, based on the AnywhereUSB's MAC address.


The steps to get this working are actually quite simple.

1. Using the "Connection List" in the AnywhereUSB Configuration Utility, point the host computer to the AnywhereUSB based on the IP address of the "router/firewall that the AnywhereUSB is attached to, or "behind".  For example, if the router/firewall's IP address is then should be in the Connection List (instead of the AnywhereUSB's IP address).

2. Because the AnywhereUSB "listens" on port 3422 TCP for USB connectivity, a Port Forwarding rule must be setup on the router/firewall, to forward inbound traffic on port 3422 TCP to the IP address of the AnywhereUSB.  As stated above, it's strongly recommended to configure the AnywhereUSB with a Static IP address (or DHCP Reservation), otherwise the Port Forwarding rule may not always be valid, i.e. if the AnywhereUSB's IP address changes via DHCP.


  • Please refer to the documentation of the router/firewall for assistance with configuring Port Forwarding (if needed), as this is outside the scope of Digi support.  Port Forwarding per se is not required, but is most commonly used.
  • A Firewall rule that passes inbound traffic on port 3422 (TCP, and optionally UDP) to the IP address of the AnywhereUSB is sufficient.

3. This step is optional and is required for the AnywhereUSB Configuration Utility to "Discover" the AnywhereUSB.  Depending on the configuration of the router/firewall - it it allows the passing of subnet broadcasts (this is a requirement) - it may or may not work.

3a. Add a second Port Forwarding rule for port 3422 UDP, which is the port that the AnywhereUSB uses for Device Discovery within the AnywhereUSB Configuration Utility (this is separate than the Digi "ADDP" discovery protocol, which is used with the Digi Device Discovery tool).

3b. Add the IP address of the router/firewall to the Discovery List ("Edit / Discovery List" in the AnywhereUSB Configuration Utility).

4. Confirm that the AnywhereUSB is connected to the host computer, the same way as if they were on the same LAN.
How to confirm if an AnywhereUSB is connected and installed properly

Related KB articles:

Connection List vs. Discovery List, in the AnywhereUSB Configuration Utility
No Remote Hubs found message in the AnywhereUSB Configuration Utility

Last updated: May 27, 2019

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