In certain rare situations, an Alta device may show as disconnected in the controller. If you happen to be quite a ways from the physical site, this could prove problematic.

However, there is a way to leverage IPv6 and SSH to gain access to the device that's in a disconnected state. This is extremely useful for avoiding expensive truck rolls and unhappy customers. In order to do this, you'll need to:

1. Discover the IPv6 LL (Link-Local) address of the device, which can be derived from the device's MAC address using the tool below
2. Have at least one Alta device online at that site OR have remote access to any non-Alta device on that site that can serve as an SSH client
3. Understand how to use SSH
4. Have SSH Keys established for the site. Please see this article on how to generate and deploy SSH keys.
5. Know what interface your local host will be using for SSH via IPv6
6. Once you have SSH'ed into the target device, you can execute common Linux commands such as ifconfig, route, ip, and udhcpc to reestablish the device's connection to the Internet/controller. In some cases, a simple reboot may resolve the issue, but we would still appreciate a Support ticket to understand corner cases where manual configuration was necessary.

IPv6 Address from a MAC Address

Rule for all platforms

Every SSH command must follow:

ssh user@[IPv6%interface]

Example:

ssh root@[fe80::beb9:23ff:fe00:f34%eth0]

Parentheses used here to show the structure — do not include them regardless of the platform.
Final real command uses square brackets only around the IPv6, not around %iface.

Windows (PowerShell or CMD)

Windows requires the %InterfaceName suffix, and it must match exactly what netsh lists.

Find interface name:

netsh interface ipv6 show interfaces

You’ll see something like:

Idx     Met         MTU          State                Name
---  ----------  ----------  ------------    ---------------------------
  8          15        1500  connected      Ethernet
 11          25        1500  connected      Wi-Fi

SSH syntax:

ssh root@[fe80::beb9:23ff:fe00:f34%Ethernet]

Or for Wi-Fi:

ssh root@[fe80::beb9:23ff:fe00:f34%Wi-Fi]

⚠ Note: Windows uses the interface name, not eth0 or en0.
⚠ Spaces in interface names (like Wi-Fi) are allowed and must remain.

macOS (Terminal)

macOS uses BSD-style interface names like en0, en1, p2p0, etc.

Find interface:

ifconfig

Look for an active interface in the same LAN as the device (usually en0 or en1).

SSH syntax:

ssh root@[fe80::beb9:23ff:fe00:f34%en0]

If you’re on Wi-Fi:

ssh root@[fe80::beb9:23ff:fe00:f34%en1]

Linux (Ubuntu, Debian, Fedora, Arch, etc.)

Linux uses predictable interface names such as:

• eth0

• enp3s0

• wlan0

• wlp2s0

• br-lan (OpenWRT / embedded systems)

Find active interface:

ip -6 addr

Or:

ip link

SSH syntax:

ssh root@[fe80::beb9:23ff:fe00:f34%eth0]

Or for Wi-Fi:

ssh root@[fe80::beb9:23ff:fe00:f34%wlan0]

Or system-dependent names:

ssh root@[fe80::beb9:23ff:fe00:f34%enp3s0]

Alta Devices

BusyBox implements the same zone index rules, but interface names differ:

Typical interfaces:

• br-lan

• eth0

Find interfaces:

ip -6 addr

SSH syntax:

ssh root@[fe80::beb9:23ff:fe00:f34%br-lan]

Or:

ssh root@[fe80::beb9:23ff:fe00:f34%eth0]