[c-nsp] When do you upgrade IOS?

[Alan Buxey]

Hi,

> 1.    What drives you to upgrade code on critical routers & switches?

new features + bug fixes. keeping the firmware up to date should be part of the
planning process - whatever network mgmt method you follow (FCAPS, ITIL, TMN, etc) upgrading
should be part of planned actions - or one day you find your whole estate running 
very old.   one advantage of keeping up to date is you read the release notes...and see
things that make you think 'oooh! thas a cool feature'...and 'ooh! thats a bug that would
hit us, glad we havent had that YET'  ;-)

> 2.    Do you upgrade code on a fixed schedule if not driven to by some other immediate requirement?

upgrades are done during advertised/known 'network at risk' period, this is early on a weekday
morning before business hours/core hours.  we also found that buy keeping the IOS reasonably up
to date...whenever another team has come to us asking for requirement/feature our switches
tend to already have that available - eg energywise or LLDP 

alan