nowledge on Network Security SSL/TLS, VPNs (IPsec, GRE), Firewall, IDS/IPS
Must have understanding on TCP/IP Header and TCP Flags.
Good Knowledge on ISO / OSI Reference Model, TCP/IP Protocol Suite, IP Addressing & Subnetting, ARP.
Switching Understanding on VLAN, STP
Knowledge of protocols such as SMTP, FTP, DNS, DHCP
Network troubleshooting experience - familiarity with tools such as Ping, Traceroute.
Knowledge on Web proxy, transparent proxy, reverse proxy, Explicit proxy & PAC files
Basic understanding on SSL/TLS, VPNs (IPsec, GRE), Firewall, IDS/IPS
Knowledge of HTTP, HTTPS
Network protocol analyzers Knowledge on anyone of these: tcpdump, Wireshark, fiddler.