1. Cisco IOS Security feature provides key features such as AAA, VPN, IPsec, content filtering, IPS, etc in all IOS based Cisco devices.
2. I like it because they include powerful security features that come with all Cisco Router and Switch from low to higher end.
3. It helped me to convert my Cisco router into a zone-based policy firewall.
4. It helped me to implement port security at my switch end.
5. I have implemented AAA in all Cisco routers and switch easily.
6. I have configured VPN server in a Cisco router with ease compare to OPENVPN configuration in a Linux OS environment.
Room for Improvement:
1. IOS security related IPS facility is not as strong as Cisco ASA and the signature file of IPS does not update automatically like Cisco ASA.
2. When I converted the Cisco router into a zone-based firewall, CPU utilization shot up and slowed down network performance.
Cisco IOS security feature is the most robust and simple security facility which nice and small to implement. It helped me protect my network from external and internal attack.