Showing results for 
Search instead for 
Did you mean: 
Cisco Employee
Cisco Employee


All Cisco Aironet 802.11a/b/g/n and 11ac Wave 1 wireless access points and bridges run IOS, except for the OEAP602.

The newer 802.11ax and 11ac Wave 2 APs, including the C9100 and 1800, 2800 and 3800 series, run AP-COS.

Note: Some very old, no longer supported, Cisco access points ran VxWorks, such as the Aironet 342 and the 1010/1020 lightweight APs.

Access Point IOS is distributed as a tar file. These tar files can be downloaded from SDS; lightweight IOS images (k9w8) are also bundled in the WLC software images (.aes.)

The AP image names include the following components:


  • platform- the access point hardware model or family supported by the image.
    Note: on an AireOS controller, the command show ap bundle shows the supported AP models and the corresponding platform names

    • ap1g1 - 700 series (702w beginning with 15.2(4)JB5)
    • ap1g2 - 1600 series

    • ap1g3 - 1530 series, AP803 embedded in IR829 router

    • ap1g4 - 1850/1830/1810 series (AP-COS)

    • ap1g5 - 1800/1815/1540 series; AP1100AC embedded in C1000 series ISR (AP-COS)
    • ap1g6 - C9117 (AP-COS)
    • ap1g6a - C9124, C9130, C9136 (AP-COS)
    • ap1g7 - C9115/9120 (AP-COS)
    • ap1g8 - C9105 (AP-COS)
    • ap3g1 - 3500/1260 series
    • ap3g2 - 3700/3600/2700/2600/1700 series (aIOS, and lightweight up through 8.4/15.3(3)JE branch)

    • ap3g3 - 2800/3800/4800/1560/IW6300/ESW6300 series (AP-COS)
    • ap801 - AP embedded in 861W, CISCO88xW, CISCO891W, 1911W routers
    • ap802 - AP embedded in 819, 812, 886VA-W/887VA-W, and C88x/C89x routers
    • apw5100 - Rockwell Stratix 5100 WAPAK9, WAPCK9, WAPEK9, WAPZK9
    • c3700 - 1700/2700/3700 series APs (lightweight, 8.5/15.3(3)JF and above)
    • c1570 - 1570 series outdoor APs
    • c1550 - 1550 (128MB model) series outdoor APs
    • c1520 - 1520 and 1550 (64MB model) series mesh APs
    • c1410 - BR1410
    • c1310 - BR1310
    • c1250 - 1250 series APs
    • c1240 - 1240 series APs
    • c1200 - 1200 series (1200/1210/1220/1230)
    • c1140 - 1140 and 1040 series APs
    • c1130 - 1130 series APs
    • c1100 - 1100 series APs (i.e. the AP1121)
    • c520 - 521 AP
    • c350 - 350 series APs
  • featureset- the set of software features supported by the image - one of:      
    • k9w7 - autonomous (or "site survey") IOS (not available with AP-COS)
    • k9w8 - full lightweight IOS/AP-COS (this is what is bundled in the WLC .aes image, and is factory installed on "mesh" APs)
    • rcvk9w8 - lightweight recovery image - this is factory installed on lightweight APs, unless a "mesh" image is specified; it lacks radio firmware (not available with COS)
    • boot - bootloader image (not IOS) - normally installed by manufacturing and not updated in the field
  • version- the IOS version       



  • Platform: c1240: 1240 series AP
  • Featureset: k9w7: autonomous IOS
  • Version: 124-25d.JA1: 12.4(25d)JA1

As AP IOS is always distributed as a tar file, the AP cannot directly execute such a file (thus, if you were to copy c1240-k9w7-tar.124-25d.JA1.tar directly onto AP flash, and then try to boot it, this could not work.)  The tar file contains, in addition to the IOS image proper, the radio firmware files, the HTML GUI files (if present), and various other files.

The AP IOS tar file must be unbundled into AP flash using the archive exec command (this is done in an automated fashion when a lightweight AP is upgraded after joining a WLC.)


AP1260#archive download-sw /overwrite tftp://


After unbundling, the IOS image itself be in a file called flash:/platform-featureset-mx.version/platform-featureset-mx.version - for example, flash:/c1240-k9w7-mx.124-25d.JA1/c1240-k9w7-mx.124-25d.JA1.  The AP is configured to boot this image if the bootloader BOOT environmental variable is set accordingly.

To see what IOS image the AP is configured to boot, examine the BOOT variable.


AP3502i#more flash:/env_vars | include BOOT



To change the BOOT variable, use the IOS config mode boot system command.




AP3502i(config)#boot system flash:/ap3g1-k9w8-mx.124-25e.JA2/ap3g1-k9w8-mx.124-25e.JA2



Thanks for this information. I struggle with how to install an IOS into an AP. And I am still not very clear on how this is to be accomplished. I have an 881W and have downloaded what I believe to be the latest IOS for this AP (ap801-k9w7-tar.152-2.JA). Problem is that I have not really found a good or at least clear set of instructions in how to load this IOS into my AP, so I have not done that yet.

Does the IOS that is currently installed into the AP remain after an update or does the new IOS overwrite the current IOS. And how does one recover from a, heaven forbid, faulty installation. What is the fallback from that. I'd appreciate any information you can point me to to help me better understand how I can update my AP. Because, right now, I am most certainly hesitant to even attempt an upgrade.

Cisco Employee
Cisco Employee

I've moved this to a new discussion thread, .


Tobias Moritz

Thank you for this very usefull document!

I see that you updated it in March to reflect the new corsica software (COS).

Could you please add the 1810 series to ap1g4?

Could you also please update the section regarding archive, image name in flash and boot variable to relect the changes COS made in comparision to IOS?


  • archive syntax is slightly different
  • archive command supports ftp even if cli help says it only supports tftp (helped me a lot, because tftp was broken in my COS version and controller join was impossible with the COS version the AP was shipped with (unsupported DTLS version and cipher suite so no auto-update possible))
  • there is no direct access to flash anymore (or someone has to reveal, how the COS equivalent to "debug capwap console cli" is called). Only two image slots "part 1" and "part 2" are visible, no files
  • boot variable cannot be set to a file name directly, only to "part 1" or "part 2"

Thank you!




Thanks for your information.

I currently use AIR-AP1572EAC.

I would like to use this Access Point in Autonomous mode, is "" valid?

Can I only use "" for the 1570 series?


Matt Wilson

The method I use to update an IOS on an AP is as follows (this deletes all config and was done on an AIR-LAP1142N-N-K9):


1. Use a laptop with Win 7 and OpenTFTP installed.

2. Set your ethernet NIC to use The AP uses as its IP address.

3. Copy the IOS file into your tftp directory that you set up with OpenTFTP. Start OpenTFTP.

4. Rename it from (for example) c1140-k9w7-tar.153-3.JD16.tar to c1140-k9w7-tar.default

5. Connect the AP to the laptop (via power supply if used).

6. Hold the reset button in whilst turning on the AP. The light should start flashing and turn red after about 20 seconds.

7. Release the reset button and the AP should pick up the TFTP server and start the upgrade. This takes about 5 minutes.

8. The AP will reboot at the end and boot into a working IOS.

9. AP can then be reconfigured using the config you (hopefully) saved before you started this process.

Muhammed Adnan

Hi Aaron,


The link to the new discussion could not be opened: .


Could you please also explain what are the major differences between COS and IOS?

How is COS different from IOS and the purpose of introducing it.

Could not find any information on COS on the internet.

Getting Started

Find answers to your questions by entering keywords or phrases in the Search bar above. New here? Use these resources to familiarize yourself with the community:

Quick Links