192.0.0.192 is the factory default IP address of older Jetdirects. It looks like your Jetdirect has either lost its existing IP address settings or failed to automatically get the correct configuration for your network using DHCP.
192.0.0.192 is very likely not an appropriate IP address for your network, so your Macbook does not know how to access it without taking some extra steps.
Since the Jetdirect 170X does not have a user interface you could use to enter IP addresses manually, it's a bit tricky to configure if the automatic configuration does not work.
First, try to perform a full reset of the Jetdirect 170X:
- Disconnect power from the 170X. Leave the network cable connected.
- While holding down the test button, reconnect power to the device. Keep the test button held down for 5 seconds after reconnecting the power.
Now print the configuration page again. If the IP address changed, then the Jetdirect managed to get an appropriate IP address from the DHCP server (a DHCP server, in a home/small business setup, is typically a built-in component in your router).
If that did not help, you may need to enter a special route command to your Macbook to allow you to access the Jetdirect. Find out the current IP address of your Macbook, then open a Terminal and type in this command:
sudo route add -interface -host 192.0.0.192 <your Macbook's IP address>
Replace <your Macbook's IP address> with the actual IP address. (Note: I verified this command on a OS X 10.9 system, the syntax may be different on older versions.) It should ask you your password, and then respond with: "add host 192.0.0.192: gateway <your Macbook's IP address>".
Now you should be able to access the Jetdirect device in its default configuration, at least until you reboot your Macbook. With "telnet 192.0.0.192" command, you should be able to connect to the Jetdirect device to manually configure its IP address parameters.
More information in this HP document: