> I assume the default gateway is +1
The default gateway is whatever IP address is assigned to the Z3 LAN. You'll be able to see this on the addressing page.
Are you using the Z3 for DHCP? If so, it will automatically give out itself as the default gateway.
Can the machine with the issue ping its configured default gateway?
If so, can it ping 8.8.8.8?
If so, can it ping google.com?