In the latter case, the packet is dropped and an ICMP Destination Unreachable message may be returned.
[1] Each router traversal counts as one hop in the distance calculation for the transmission path.
The device to which the default route points is often called the default gateway, and it often carries out other functions such as packet filtering, firewalling, or proxy server operations.
The default route in Internet Protocol Version 4 (IPv4) is designated as the zero address, 0.0.0.0/0 in CIDR notation.
In the highest-level segment of a network, administrators generally point the default route for a given host towards the router that has a connection to a network service provider.