To configure the default gateway for the switch, use the ip default-gateway command. To start your switch, you need to follow the procedures in the Getting Started Guide or the hardware installation guide for installing and powering on the switch and for setting up the initial switch configuration (IP address, subnet mask, default gateway, secret and Telnet passwords, and so. A default gateway is a crucial network configuration parameter that allows devices within a subnet to communicate with devices outside of that subnet, including the internet. This. Layer 2 Switch is an indispensable part of Network setup in LAN environments.