Understanding IOS Levels & Vulnerabilites

[RFC1795]

Hi

Does anyone have a good explanation on how the IOS levels, trains work? I'm looking into various IOS levels along with vulnerabilities and sometimes I get confused as to whether or not a level is actually vulnerable.

Take this for example. If a device is running "124-6.T7" version of IOS, the Cisco page says for 12.4T the first fix was in these versions:
12.4(15)T8
12.4(20)T2
12.4(22)T
12.4(15)T9

I'm thinking 12.4(6)T7 is affected, or would it not be as T7 is higher than say T2 in the above? Or is it the (6) that is the important bit?

Thanks

 

[rassoulghaznavi]

Try cisco feature navigator
It will help you to find the required IOS,
Also when you try to download and IOS from Cisco web site it will give you all information, as well as any volnerabilities if there is any.

http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp

Rassoul - Network/system engineer
CCNP
CCIP
CCNAV
IIUC2
LPI

http://www.net-grp.com