- Routing: IS-IS, EIGRP, RIP, OSPF, BGP, NAT, PAT, PBR, MPLS (MPLS-VPN, EoMPLS, VPLS)
- Switching: VLANs, VTP, dot1q, q-in-q, Rapid PVST+, MSTP.
- Network security: VPNs (IPSEC, IPSEC/GRE, DMVPN), Port security, DHCP snooping, dynamic ARP inspection, IP source guard
- High Availability: HSRP, VRRP, GLBP, Etherchannel, SSO, IP SLA.
- WAN: PPP, PPPoE, PPP Multilink, HDLC.
- Cisco PIX: NAT, Failover, Remote VPN, ACLs.
- QoS: Traffic policing and shaping, traffic prioritization.
- Linux - Apache, bash, mysql, varnish, Nginx
- Juniper and Cisco