Hi, you can serch IOS version by features that are required on your network, ex: VIOP or PIM sparse mode. By using the feature navigator you can find out which IOS has the features you want. Your 8510 may support vlans depending on the IOS version. Also from config t mode see if you can create a vlan by typing vlan ?. HTH See the post below.
Store-sw1(config)#vlan ?
WORD ISL VLAN IDs 1-4094
access-map Create vlan access-map or enter vlan access-map command mode
dot1q dot1q parameters
filter Apply a VLAN Map
internal internal VLAN
Welcome to Cisco Feature Navigator
Cisco Feature Navigator allows you to quickly find the right Cisco IOS and CatOS software release for the features you want to run on your network.
http://tools.cisco.com/ITDIT/CFN/jsp/index.jsp
