I need to know on IOS upgrade licensing. I have five Cisco 2811 routers and we have provided the maintenance contract to one of a vendor. They support hardware and IOS. However in the contract it was mentioned if we want to upgrade the IOS it is chargeable. Now my question is, if I buy the IOS from this vendor, should I have to pay for all the 5 devices or I can buy the IOS file for one device and copy it to all devices and upgrade by myself. I need to know is it legal to buy IOS file and use it to 'n' number of devices. Also please let me know if I can buy IOS directly from Cisco.com.