As far as wired connections via ethernet cables are concerned, wireless connections can never really be considered absolute or reliable, as in here exists the physical mode of connection, therefore, with minimal variation on part of the user. As you configure your Linksys re6500 setup, plug in an ethernet cable between your router and the extender. It allows hassle-free setup and successful operation. Also, plug in your extender to your device with the aid of ethernet wires. While doing so, make use of only the original wires that came inside the box. They are superior wires that can carry signals more effectively. Periodically check those ethernet wires and ports to keep the connection strong and safe. Once the older ones have been put to use for quite some time, they must be replaced.
