I have a cisco 2600 router with IOS version c2600-i-mz.120-10. Its not supporting the encapsulation dot1q command to route the vlans. How can this router be used to route the vlans ????? If I have to upgrade my IOS where shall I do it from ?? This router allows me to create sub interface but doesnt allow me to bind a vlan to the sub interface neither does it let to add the ip address. I dont know how to use this router !!!!!!!!!!!!

Can secondary ip addresses kept in interfaces be used in routing alogrithms like OSPF ?? Can we assign secondary ip address of the same interface as private ip whereas the main ip is public ????