Designed dual-homing Backbone connectivity to corporate global network providing load balancing and dynamic fail-over. Optimize route propagation, control and filter when redistributing between OSPF and EIGRP Implemented 3-Tier Hierarchical Network architecture based on design best practice and business needs. Utilized Layer2 SSO, Layer3/SSO+NSF features to provide network high availability. Optimized Spanning Tree root selection based on HSRP active Vlan state Improved routing protocol convergence by tuning protocol metric calculation to allow multiple feasible successor and route aggregation to reduce queries Lead the security project of deploying site to multi-site redundant IPsec/VPN. Designed to allow VPN clients access remote networks through VPN gateway, configured gateway to allow SSLVPN access Presented and implemented Network Admission Control solution using NAC appliance to enforce network policies Deployed wireless network with 4400 WLAN controller and 1200 series APs