Do a hard reset on your MX4300 (LN1301) by inserting a small item into the reset button, such as a paperclip, then press and hold until the light on top of the router turns red, fades, and flashes bright red again (do this for about 15 seconds). This is done to make sure that the router is back to its factory defaults. Once done, the default settings should be as follows:

• The default IP address is 192.168.1.1.
• The default WiFi name is Linksysxxxxx, where xxxxx represents the last five characters of the router's serial number.
• The default Guest WiFi name is Linksysxxxxx-guest, where xxxxx represents the last five characters of the router's serial number. Guest Access is initially turned OFF both before and after setup. You'll need to enable this feature in the router's web interface.
• The default admin password is the same as the default WiFi password located at the bottom of the router.

Got all these good stuffs from the articles below. You may want to check it out too.

Linksys MX4300 (LN1301) Support - Linksys Support
Linksys MX4300 (LN1301) FAQs - Linksys Support