The Linksys re6400 extender comes with its default credentials that need to be changed after the setup. In addition to that, you must make changes in some physical factors of the extender. Doing so will enable you to get the optimized performance of the extender. So, once you complete the Linksys re6400 setup, relocate it to another place and preferably place it centrally. Placing the extender at this location will allow it to deliver the internet signals at every corner. Whereas, talking about some internal modifications, try to update the default login details that include the username and password. The default password is easy to access that’s why there can be some unauthorized users to the network. Apart from that, set a new SSID network name of the network to give it a unique identity. Lastly, choose the WiFi channels for the extender which are less congested and different from your neighbor’s networks.