What will happen if the default gateway is not specified on your computer and you try to reach another network?

If a default gateway is not specified on a computer and an attempt is made to reach another network, the packet will not be sent. A default gateway acts as an intermediary for traffic destined for networks outside the local subnet. When the computer attempts to communicate with an address outside of its own local network and lacks a specified gateway, it will be unable to resolve how to properly route the packet. As a result, the data will not leave the local network because the device does not have the necessary routing information to send it outside.

This situation illustrates the importance of having a correctly configured default gateway, as it is essential for facilitating communication with devices that reside outside of the local network segment.