When a homeowner moves and sets up a new router for the new ISP it is important to take appropriate security measures to protect their network from potential security threats. The FIRST step that the homeowner should take after installation of all relevant cabling and hardware is to change the default passwords on new network devices.
Most modern routers come with default usernames and passwords that are widely known to potential attackers.
If these defaults are not changed, it could make it easier for external attackers to gain unauthorized access to the network. Changing the passwords on new network devices is a simple but effective way to improve the security posture of the network.