Understand Access Point IOS Images

All Cisco Access Points and Bridges are normally shipped with IOS, except Office Extend AP602. Some of the old AP’s don’t run IOS (Example: Aironet 340, 1000 Series AP).

Normally Cisco AP IOS is distributed as .Tar file.

The nomenclature of the image follows as or The IOS image names include the following components:

platform–featureset-tar.version.tar

Platform: The access point hardware model or family supported by the image

Example:

ap1g1 – 700 series
ap1g2 – 1600 series
ap1g3 – 1530 series
ap3g2 – 3700/3600/2600 series (3700 supported beginning with 15.2(4)JB)
ap3g1 – 3500/1260 series
ap802 – AP embedded in 819, 812, 886VA-W/887VA-W, C88x and C88x routers
ap801 – AP embedded in 861W, most 88xW, and 1911W routers
c1520 – 1550 and 1520 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
k9w8 – full lightweight IOS (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

Version– the IOS version

There is a 1:1 mapping between the lightweight IOS software version (such as 12.4(23c)JA) and the CUWN version (such as 7.0.98.0).

See the Cisco Wireless Solution Software Compatibility Matrix

Example:

c1240–k9w7-tar.124-25d.JA1.tar

• 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.)

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.