unable to login to the web interface of my Nighthawk 5400

Hi don't know if you solved this issue yet but for those who are looking for a possible answer here it is.

1. Disconnect Internet port.

2  Wait a few seconds (device needs to detect that internet is no longer available)

3 Connect computer via ethernet. (do not use a USB adapter it will most likely fail)

4 Clear cookies / cache ( you want to avoid reusing a bad login attempt)

5 Open Web browser http://"ip_address" (example: http://192.168.1.1) 

               - do not use "https://"

6 Enter credentials   username: admin          password: "your password"

Unfortunately the firmware has a bad "intrusion detection" rule.

Not much you can do to fix it but this is a workaround to access your router.

When you disconnect the internet cable the WAN rule set changed to LAN rule set

Hopefully this will be addressed soon in other models as well