Hi Dean,
Firstly, you need to decide whether you need EMI (Enhanced Multilayer Software Image) or SMI (Standard Multilayer Software Image) software feature set.
The following features and functionality are supported with the Enhanced Multilayer Software Image:
• Dynamic IP routing protocols for load balancing and constructing scalable LANs:
–Open Shortest Path First (OSPF)
–Interior Gateway Routing Protocol (IGRP) and Enhanced IGRP (EIGRP)
–Border Gateway Protocol (BGPv4)
• Policy-based Routing (PBR) allows superior control by enabling flow redirection regardless of the routing protocol configured
• Protocol-Independent Multicast (PIM) for IP multicast routing within a network that enables the network to receive the multicast feed requested and for switches not participating in the multicast to be pruned-support for PIM sparse mode (PIM-SM), PIM dense mode (PIM-DM), and PIM sparse-dense mode
• Distance Vector Multicast Routing Protocol (DVMRP) tunneling for interconnecting two multicast-enabled networks across non-multicast networks
• Private VLAN (PVLAN) provides the ability to restrict communications between hosts at layer 2 through the use of primary and secondary VLANs.
The SMI supports basic RIP and static routing but does allow. Both the SMI and the EMI allow for Layer 3 and Layer 4 lookups for QoS and security.
If you have need more advanced services, you can go for the Advanced IP Services License, which gives you IP46 and advanced ip services functionality...
Once you have made the above selection on feature set, you need to work out which particular release you are going to go for. Read the Release Notes for some of the newer one to see if there are any caveats that may apply to your setup.
Once you have done so, use Cisco Software Advisor, or IOS Upgrade Planner to determine flash/DRAM requirements for your chosen version. If you don't have sufficient memory, either upgrade your memory (unlikely in your case) or drop to an older version...
Then, I would do some testing with this IOS in your labs before approving them for production use.
Hope that helps - pls rate posts that help.
Regards,
Paresh
