What is the impact if the default gateway is misconfigured on a host?

When the default gateway on a host is misconfigured, the most significant impact is that the host can communicate with local networks but not with remote ones. The default gateway is a key component in a network's configuration, serving as an access point that routes traffic from a local network to outside networks, such as the internet.

In essence, a correctly configured default gateway allows the host to send data packets to destinations outside its local subnet. If this gateway is misconfigured — whether due to an incorrect IP address or another error — the host is unable to route packets properly beyond its local network. As a result, it can still communicate with devices on the same local subnet or network segment, since those devices do not require routing through a gateway. However, attempts to access resources outside of this local environment, like the internet, would fail because the traffic cannot be directed correctly to reach those broader networks.

This is why the impact of a misconfigured default gateway primarily limits the host's ability to access remote networks while still permitting communication on the local network.