https://hugo.fryguy.net/tags/catos/Catos - Tag - Fryguy's BlogHugo -- gohugo.ioenMon, 15 Aug 2011 12:05:06 +0000https://hugo.fryguy.net/2011/08/15/catos-and-ios/Mon, 15 Aug 2011 12:05:06 +0000Fryguyhttps://hugo.fryguy.net/2011/08/15/catos-and-ios/
Ahh, Catalyst OS – old skool Layer 2.  There is a dwindling number of engineer who have seen this code, let alone have ever used this code and understand it.  Since I am about to convert some of the CatOS switches at work to IOS, I figured I would share some of the basics and joys of CatOS with you. Ok, perhaps I am just reminiscing a bit here – but if this can help just one person, then all is good – right?
So, what is this thing called CatOS one might ask.  Well, in short it is Cisco OS that is Layer 2 only; there are no routed interfaces, no IP addresses on interfaces (well, there is SC0) or IPs for VLANS – just L2 VLANS and Ports.  When a Catalyst switch is running CatOS for Layer 2 it is called Hybrid mode – if the switch is running IOS for Layer 2 and Layer 3, it is called Native mode.  CatOS dates back to 1993 when Cisco acquired Crescendo Communications in 1993 and the Catalyst line – its first foray into Switching – and because of the wide acceptance of XDi/CatOS, the OS has lived on for many years.  As the Catalyst line moved forward from the 5000, to the 5500, and now the 6500 – CatOS has survived.  It is only recently ( Dec 2010 ) that Cisco is no longer fixing and producing CatOS code, and CatOS code will finally go End-Of-Support in December of 2014.
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