curl -I -H "Pragma: akamai-x-cache-on, akamai-x-cache-remote-on, akamai-x-check-cacheable, akamai-x-get-cache-key, akamai-x-get-extracted-values, akamai-x-get-ssl-client-session-id, akamai-x-get-true-cache-key, akamai-x-serial-no, akamai-x-get-request-id,akamai-x-get-nonces,akamai-x-get-client-ip,akamai-x-feo-trace" http://www.xyz123.com/style.css

A typical Set of Request and Response Headers follows:

Request Headers

Accept text/css,*/*;q=0.1
Accept-Encoding gzip, deflate
Accept-Language en-us,en;q=0.5
Cache-Control no-cache
Connection keep-alive
Host www.website.com
Pragma akamai-x-cache-on, akamai-x-cache-remote-on, 
akamai-x-check-cacheable, akamai-x-get-cache-key, 
akamai-x-get-extracted-values, akamai-x-get-nonces, 
akamai-x-get-ssl-client-session-id, 
akamai-x-get-true-cache-key, akamai-x-serial-no
User-Agent Mozilla/5.0 (Windows NT 6.1; rv:11.0) Gecko/20100101 Firefox/11.0

Response Headers

Cache-Control private, max-age=1103
Connection keep-alive
Content-Encoding gzip
Content-Length 9120
Content-Type text/css
Date Sun, 18 Mar 2012 10:59:33 GMT
Etag W/"34608-1330928498000"
Last-Modified Mon, 05 Mar 2012 06:21:38 GMT
Server Apache-Coyote/1.1
Vary Accept-Encoding
X-Akamai-Session-Info name=PARENT_SETTING; value=TD
X-Cache TCP_MEM_HIT from a118-214-191-15 (AkamaiGHost/6.7.0.2-9183648)
X-Cache-Key /L/1745/15811/3h/www.website.com/common/css/style.css
X-Check-Cacheable YES
X-Serial 1745
X-True-Cache-Key /L/www.website.com/common/css/style.css
ntCoent-Length 34608

Explanation on some of the Akamai debug headers:

X-Cache : Cache State

X-Cache TCP_MEM_HIT from a118-214-191-15 (AkamaiGHost/6.7.0.2-9183648)
a118-214-191-15 : Akamai IP Identifier (The Akamai server that serves this request)

• TCP_HIT : The object was fresh in cache and object from disk cache.
• TCP_MISS : The object was not in cache, server fetched object from origin.
• TCP_REFRESH_HIT : The object was stale in cache and we successfully refreshed with 
  the origin on an If-modified-Since request.
• TCP_REFRESH_MISS : Object was stale in cache and refresh obtained a new object from 
  origin in response to our IF-Modified-Since request.
• TCP_REFRESH_FAIL_HIT : Object was stale in cache and we failed on refresh (couldn't 
  reach origin) so we served the stale object.
• TCP_IMS_HIT : IF-Modified-Since request from client and object was fresh in
  cache and served.
• TCP_NEGATIVE_HIT : Object previously returned a "not found" (or any other negatively
  cacheable response) and that cached response was a hit for this
  new request.
• TCP_MEM_HIT : Object was on disk and in the memory cache. Server served it 
  without hitting the disk.
• TCP_DENIED : Denied access to the client for whatever reason.
• TCP_COOKIE_DENY : Denied access on cookie authentication (if centralized or 
  decentralized authorization feature is being used in config).

X-Cache-Key : Internal Cache Key

X-Cache-Key /L/1745/15811/3h/www.website.com/common/css/style.css
15811 : Akamai CP Code
3h : Cache TTL
www.website.com : Origin Server Name

X-Check-Cacheable : Cacheability

This determines if the request object is cache-able as set in your Akamai configuration.