Cisco – Comparing Cisco IOS Versions vs Cisco ASA Versions

ciscocisco-asacisco-commandscisco-ios

I'm very confused by Cisco versions, but perhaps I'm just over thinking it. Are IOs versions and ASA versions the same? E.g. If I have an ASA 5510 and I type

show version

and it comes back with

Cisco Adaptive Security Appliance Software Version 8.3(2)
Device Manager Version 6.9(4)

does that mean it's running IOS 8.3?

Or will accept IOS 8.3 level commands?

Or do ASA devices have their own version separate from the IOS versions?

(p.s. the version numbers above are made up so they won't make sense).

More generally, how do you know which commands a Cisco device is going to accept? If you show up at a clients and start trying to do named access lists (which apparently started with IOS 11.2?) how do you know if they are going to work? Or do you just try, curse and revert to older commands on the fly if they aren't recognized?

I've searched long and hard and nothing seems to show what versions which commands should work on.

Best Answer

Cisco has a whole bunch of different operating systems for a variety of products:

IOS runs on most Cisco routers and switches.
IOS XE is a more modern, modular version of IOS.
IOS XR runs on high-end routers.
NX-OS runs on the Nexus line of datacenter switches.
ASA OS runs on Cisco ASA devices.
AireOS runs on Access Points.
And I'm probably forgetting a lot of other devices and appliances.

Version numbers for all these operating systems are unrelated. And even within the same OS there can be different release trains for different platforms.

If you want to know which commands should work on a specific device, you can check the Cisco Feature Navigator.

Related Solutions

Cisco IOS CLI – How to Identify the Interface Being Configured

AFAIK, the answer is NO. I never understood how this valuable feature has escaped IOS for so many years or I manged to never discover it. ;-)

I use the following technique in some cases when I want to be absolutely sure I'm configuring the interface that I think I am. Comments (!) shown. I know this technique is long-winded for the net vets, but it fits perfectly with the paranoid crowd which is sometimes both.

conf t
do sh run int g1/1
! Look over int config and note description
int g1/1
 desc GiveMeThisInterfaceOrGiveMeDeath
 do sh run int g1/1
 !Confirm the int you think you're inside configuring is the one intended
 <config-if commands here>

How to Choose the Right Cisco ASA Software Release

In general, how do you decide which ASA software release to upgrade to?

If the newest major release has been out for a while, I look at the release notes to get a sense if there are no bugs that would affect my network and pick a minor version based on that. Else, I go with the newest version of the second-newest major release--assuming that doesn't have open bugs that would affect my network.

Is there a way to get a sense for how stable a particular release is?

Absolutely, look at the open caveats in the release notes. For software that's been in the wild for a reasonable amount of time, the shorter the list of open caveats, the better. This has held true in my experience going back to 6.x.

What does the .ED suffix mean? What does a numeric .x suffix mean?

ED = early deployment -- "Early Deployment releases offer new feature, platform, or interface support. Most non-major releases contain ED releases." This is a flag to tell you that there's something new--read the release notes as you say but it's usually benign in my experience. A fourth number (.x in your question) is a "interim release" that replaces another version previously released. For 8.4(4.1) ("8.4.4.1" above) there was a "build problem" with 8.4(4) so 8.4(4.1) was put out to replace it.

Can I glean stability of a release based on the age of major and minor releases? For example, should I expect 8.4.7.ED to be more stable than 9.2.1.ED?

Maybe. I'd definitely say 8.4.7, as an example, would be more stable than 9.0 or 9.1, but a point-2 release could have reached sufficient maturity. It really depends on the open caveats and your specific config and use case.

Best Answer

Related Solutions

Cisco IOS CLI – How to Identify the Interface Being Configured

How to Choose the Right Cisco ASA Software Release

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