What is the primary purpose of a default gateway in a local network?

The primary purpose of a default gateway in a local network is to serve as a point of access to external networks. A default gateway allows devices within a local network to communicate with devices on different networks, such as the internet. When a device on the local network needs to send data to an external destination that is not part of its own subnet, the data packet is sent to the default gateway, which then forwards the packet to the appropriate external network. This is essential for enabling communication beyond the local network's borders and for accessing resources outside of the local environment.

In contrast, the other functions listed pertain to different networking roles. Assigning static IP addresses is typically done by a DHCP server or manually configured by network administrators. Filtering incoming and outgoing traffic is generally the role of firewalls or security appliances, while translating IP addresses to domain names is handled by DNS servers, which resolve human-readable domain names into corresponding IP addresses.