Category Archives: Cisco


Wireless – incorrect password…except when its not

A family member recently purchased a new Hisense 50″ smart TV but was having no end of problems connecting it to their home wireless.  They assured me the password was correct but the TV would have none of this, the only error being incorrect password.

When I started looking at this issue I was sure the TV was not sending the right password, either the password was not being entered correctly or it was being truncated etc,  but after an hour or so it was clear there was not a simple fix for this issue.  All other wireless devices (android, iphone/ipad, macbook, HTC) had no issues connecting to the network.  The TV itself successfully connected to the wireless hotspot on both the HTC and the Android so why would it not connect to the Cisco 857w?

Troubleshooting steps were along the lines of:

  • Double and triple checking the password entered with the remote
  • Changing the ssid to remove the dash (-) character in case there were issues using non standard characters
  • Changed the password to 8 characters in case the original one was being truncated for some reason
  • Configured the wireless settings on the TV manually in case it was not correctly identifying the security type (wpa/wpa2)
  • Ran debugs on the router
  • Running a wireshark capture on another laptop to check for frames sent/received from the TV’s wireless card
  • Lowered the MTU on the wireless interface and repeated the debugs

Combining the last three points, should have given me an indication of the actual problem.  The debugs on the router came up empty and also the wireshark capture did not show ANY frames which matched the MAC address of the TV, tweaking the MTU settings also did not change the outcome of these two things.  The only error message from the router was “authentication failed” and from the TV was “incorrect password”.

Lots of googling didn’t turn up a great deal other than what I had already tried and then I ran across some mentions of an issue where the device simply reported the “authentication failed” error but where it was 100% the correct password which also seemed to be the exact problem I was experiencing.  This was related to the wpa handshake timeout value, the only problem was that these articles were all for the CIsco aironet products but here I was using a Cisco 857w.

After lots of trial and error on the cli to try and find the correct hierarchy to change the timeout value, I found a random link on Zebra technologies website which was referring to a hidden command on a ‘Cisco access point” – Zebra Technologies

Here it is mentioned that this is a hidden global command on the access point.  Having not gotten any further I remember that you can activate hidden commands on the 857/877’s with the “service internal” command, this again did the trick.  Once I reset the wpa timeout value, the TV immediately connected to the wireless network.

The actual commands I used to change the wpa handshake timeout value and fix this issue are as follows:

Router(config)#service internal
Router(config)#dot11 wpa handshake timeout 2000