Wifi Access Points
- Thread starter alex1002
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I recently pick up one of these for cheap and immediately ran into a couple of gottchas.
1. If you buy one with the "Lightweight" firmware you'll need a controller.
2. You have to properly power the AP with either a Cisco POE injector or a local PSU (Cisco only).
I bought a controller but the POE ports weren't enough to power the AP so now I'm waiting on an ejector tp arrive. While it's true the AP is cheap, there are hidden costs.
If you only have a single radio module fitted, the AP should work with any standard 802.3af capable switch or injector. However, if you have two radios installed then it's power draw on average is around 16.5 watts, which is outside spec for 802.3af, and will require either a catalyst switch that supports cisco's enhanced poe, another capable switch or a midspan injector capable of supplying 18 watts per port. If you buy the wrong AP to begin with, as Fitz mentioned, you will need a wireless controller to be able to boot it. Before buying, check the actual part number. The lightweight AP's begin AIR-LAPxxxx, the standard autonomous AP's begin AIR-APxxxx. If my old memory is working, you can put lwapp onto the autonomous AP's, if you want to run them with a controller, but you can't put the standard autonomous firmware on the LAP's 
With only a single radio fitted, it should only be pulling around 12 watts, just under 802.3af spec, so it should be able to handle it, but maybe it's just on the edge and your PSE is rejecting it. How long is the run between controller and AP? Could you be suffering from a line drop? The voltage output of that midspan injector you ordered should drop to -48V on line at max load. POE+ (802.3at) rated @ 30W?
Right now the run between the AP and controller is 3 feet. The injector I was using is a TP Link, not exactly enterprise grade.
The injector that goes with this AP is rated at 57vdc, surely a standard ejector doesn't output this high a voltage?
EDIT : Just checked the TP-Link injector. Output is 48vdc. Bet that's the problem.
The injector that goes with this AP is rated at 57vdc, surely a standard ejector doesn't output this high a voltage?
EDIT : Just checked the TP-Link injector. Output is 48vdc. Bet that's the problem.
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POE (802.3af) should be -48vdc @ 35mA, the newer higher power POE+ (802.3at) is rated -57vdc @ 60mA if my memory seves me correctly. Check the curent rating of your supply/ injector, I suspect the TP-Link one you have is only POE (802.3af) capable, although it doesn't really explain why it won't work with a single radio fitted. I'm sure it will be fine with the new one though
You can convert back to autonomous mode using this procedure, assuming you have access to the correct firmware image. If you don't have a Cisco contract, Google is your friend. You can get the filename and MD5 checksum from the Cisco site without needing a login, then find the image elsewhere and verify it has the same MD5 checksum.
True. Although you can use a Cisco POE switch or a 3rd-party POE injector (as long as it is noted as supporting the 1250). I use the PowerDsine PD-90xxG units (in particular, the PD-9024G/ACDC/M/F which is the top-of-the-line model). I see an eBay listing (search for 121860337015) for a pair of 6-port injectors for $80. Those do have the management Ethernet as well as the basic injector. If you are looking for a 24-port model and want to power 24 Aironet 1250's, you need the "/F" (full power) model. The non-F 9024G's are only rated for 12 Aironet 1250's. The 6- and 12-port injectors dont' have this limitation. "/M" indicates the unit has the management Ethernet. If you do get one of these, PM me for the latest firmware as the manufacturer's support site is broken and they're not interested in fixing it (but will send out firmware on request).
Not on short cables. Voltage drop depends on the current drawn by the AP and the resistance of the cable (assuming the power injector is capable of producing the necessary current in the first place).
The idea is for the AP to see 48V at its end of the cable. If you start with 56V, you can have a much longer cable before it drops to 48V at the AP end.
Most things that expect "48 Volts" are using Telco-style power supplies (the central office battery voltage is -48 to -56) and are pretty forgiving of out-of-range voltage.
You can only switch between LWAPP and Autonomous Modes on the standard AP by flashing the appropriate firmware, not on the lightweight AP's. Those need a wireless controller to boot from.
No, the lightweight and autonomous APs have the same boot rom (which Cisco calls ROMMON). The procedure I linked involves using the Mode button to enter the ROMMON CLI and downloading the new image.
There is also a way to do it from the minimal console you get when the AP is running in Lightweight mode:
Code:
debug lwapp console cli
debug lwapp client no-reload
archive download-sw /overwrite tftp://a.b.c.d/filename.tar
reload
Code:
config term
interface gi0
ip address w.x.y.z 255.255.255.0
exitI seemed to remember something about the Lightweight AP's not having sufficient flash onboard to hold the autonomous image, but now having checked, I'm wrong.
It is model-specific. Most of the ones that run IOS are OK, but some of the ones with VxWorks or similar don't have enough flash. The 1250 was a flagship product back when it came out, so it got the full IOS, 2 radios / 6 antennas and lots of memory.
Of course, Cisco's idea of "lots of memory" is usually "not enough" by the time a product is a few years old. That may be why they have stopped releasing new Autonomous releases for the 1250, but the Lightweight releases continue. Or it could just be that they have a big customer with enough clout that wants Lightweight - the Catalyst 3550 switches were End-of-Life for years, but Cisco still produced builds for one model (DC power) due to a Telco that had a whole bunch of them and was willing to pay. In that case, that firmware would run on the other 3550 models if you tried it, but of course it wasn't supported.
The last Cisco air product I actually used was the venerable 1231, but my hay day was when the 350 bridges were all the rage
I've searched but cannot find
The WLC 2106 is compatible with the 1250 but I can't find any reference as to whether or not the POE has enough juice to power it. It can't even with one radio removed. So I'm wondering what the purpose of POE is in this controller.
The WLC 2106 is compatible with the 1250 but I can't find any reference as to whether or not the POE has enough juice to power it. It can't even with one radio removed. So I'm wondering what the purpose of POE is in this controller.
Both POE ports on the WLC 2106 are only capable of 802.3af, so they can only source 15.5W, which is I suspect borderline for that AP with only 1 radio fitted. It "should" be able to power it, with only a single radio fitted, as I've already mentioned, but it's close. To do that AP justice you need a PSE or Midspan Injector capable of sourcing a minimum of 20W, which means POE+ (802.3at) or what Cisco call "Enhanced POE". Although the WLC has POE capable ports on it, they really expect you to power your devices from an POE+ capable Switch
If you have never used any of the Cisco AP's with a WLC before, it can be a bit of a mare to get going with them. Unless a static IP has been assigned, the first thing they will look for on power up is a DHCP server then they'll want to register with the WLC, become neighbours etc etc.
Cisco do have some very detailed documentation on their site to help you get going though, but it's a hard read if your not familiar with the jargon etc
If you have never used any of the Cisco AP's with a WLC before, it can be a bit of a mare to get going with them. Unless a static IP has been assigned, the first thing they will look for on power up is a DHCP server then they'll want to register with the WLC, become neighbours etc etc.
Cisco do have some very detailed documentation on their site to help you get going though, but it's a hard read if your not familiar with the jargon etc
I managed to reset it and get into the Web UI all by myself..... And then promptly forgot I setup port one as the management port. Scratched my head for a bit when I could no longer access the Web UI when I plugged the cable into another port. I'm all set and waiting for the injector. Just got shipping notice today. It's due to arrive Friday.
I can't get the LAP1252AG-A-K9 t0 show up as an AP. It shows up as an "interface neighbor" and it pulls an IP but it doesn't show up as a AP either in the 2106 nor wireless. I also have a LAP1131AG-A-K9 which works like it should so I know the controller is OK.
Also, I can't access the web interface on either of these APs.
Anybody have any ideas?
Also, I can't access the web interface on either of these APs.
Anybody have any ideas?