Tag: cisco

Cisco Aironet wireless access point LED light not lit

cisco 3500eTypically the LED on Cisco Aironet wireless access points glows a soothing blue color if a client is associated, or a steady green if it is patiently waiting for someone to join it’s network and share its amazing WLANs.  Today I ran across an interesting problem that I hadn’t seen before.  One Cisco Aironet 3502e access point had an LED was not lit. Typically, this happens when an access point is not getting power.  It is usually caused when the AP is unplugged or has a power supply that is bad.  In this case, the access point was powered by power over ethernet (POE), and I could tell that it was getting power (the command ‘show power inline’ on a Cisco switch will tell you which switchport is supplying power and how many watts are being consumed). The switch also showed it’s status was ‘connected’ so I knew it had a valid ethernet link.  Hmmm..strange.   The Cisco Wireless Lan Controller (WLC) also showed the access point as booted up, connected and generally happy.   Why no LED?  Weird…. Then I shamefully fell into the old windows method of troubleshooting: “When all else fails, reboot!”  I disrupted the power to this remote access point by shutting down the switch interface and brought it back up, but it still had no LED light, not even during the reboot.  (At that point I may have uttered an obscenity under my breath, but don’t tell anyone.)  Since this access point was around 1000 miles away and over 20 feet off the ground, I didn’t really want to tell the end user to get on a lift and swap it out, and I didn’t want to tell them it was working fine as it obviously wasn’t from their perspective.    I did a little research and found there is a bug in Cisco’s access point code that causes the LED light to disable itself.  Nice.  Luckily the fix is easy, and it doesn’t require a software upgrade.  Just run the following command from the CLI of the Wireless Lan Controller (WLC).

wlc>config ap led-state enable all

That fixed it for me.  Happy blue and green lights for the end-user, another satisfied customer for me.    Hopefully you can get similar results if you run across the same problem in your wireless networking troubleshooting adventures!



Linksys (Cisco) e2500 or n600 external antenna mod


linksys e2500Recently, I acquired a new linksys (Cisco)  e2500 (a.k.a n600) wireless router.  I wanted to use it to replace or mesh to an older D-link that I had in the basement of our four-level split.  I was having some issues with a weak signal from the dlink and wanted to fix that.  Also, I knew the E2500 was fully supported by DD-WRT, the open source, very flexible wireless software.

The first thing I tried was flashing ddwrt to the new wireless router, and setting it up as a bridged repeater.  That mode will associate to the current wireless ssid from the dlink, and broadcast its own ssid;  essentially extending the current network.   It was pretty easy to set up using instructions on the ddwrt site. Now I had two ssids I could use in my house,  one in the basement and one in the upstairs rooms.   Although it worked, I wasn’t happy with the performance.  The link between the two routers was pretty sketchy, and I would get occasional drops.

Linksys e2500

The Linksys e2500- great router for the money, but it has a fairly weak signal

So on to Plan B: Use the Linksys n600 (Cisco) E2500 in the basement and get better coverage around the house.

This plan also proved a total failure.  I needed something a little more powerful–even through with DD-WRT I could turn up the transmit power, the Linksys still did not give good enough coverage throughout the house.


Add four external antennas to the Linksys e2500!  There are kits available on ebay that will get you everything you need to crank the wireless coverage and satisfy your need for nerdification!

I bought a kit on ebay for about $24 that includes two 6db, two 7db and four pigtail connectors for this project.  It requires some soldering, and will allow you to extend your 2.4 and 5 Ghz bands.  If you are not nerdy enough to solder, order the two-antenna version (but it only will increase the 5GHz signal (A-band), not the 2.4 (b/g band).  So older wireless cards and older laptops may not benefit at all.

Opening the Linksys E2500

linksys e2500 warning

Yes, that’s right–I void warrantees. If you want to keep your warranty, don’t do this, or stop here and buy a $300 wireless router with better coverage.



1.) There are three screws on the bottom of the unit, flip it over.   The screws are located under the three rubber feet.  Remove all three screws and set them aside.






2.  Use a plastic wedge to pry the cover off.  I used a guitar pick, which really worked well.  I also had a small plastic ipod tool that came in handy as well.  Be careful not to damage anything, this is where patience and nerdyness meet.

inside of Linksys e2500

Ahh, finally, a look inside the linksys e2500.  Notice the fine tablecloth I am careful not to damage.