1. Network Infrastructure

1.1 OSI Model

• Core Requirements: In-depth understanding of layer functions and protocols (focus on Transport/Network layers)
  • Key Protocols:
    • Transport Layer: TCP (3-way handshake/sliding window), UDP (low-latency特性)
    • Network Layer: IP (fragmentation/TTL), ICMP (Ping/Traceroute)

1.2 TCP/IP Protocol Suite

• Core Competencies:
  • IP Addressing: Subnetting (VLSM/CIDR), IPv6 transition technologies
  • Key Protocols:
    • ARP (Address Resolution/Proxy ARP)
    • DHCP (Address allocation process)

2. Routing and Switching

2.1 Routing Protocols

• IGP Actual combat:
  • OSPF: LSA types, Area design (Stub/NSSA)
  • EIGRP: DUAL algorithm, Feasible Condition
• BGP Advanced:
  • Path Attributes (AS_PATH/LOCAL_PREF)
  • Route Reflectors & Confederations

2.2 Switching Technologies

• Core Technologies:
  • Inter-VLAN Routing (SVI/Router-on-a-Stick)
  • STP Optimization (PortFast/BPDU Guard)

3. Network Security

3.1 Security Devices

• Firewalls: Stateful inspection/NAT policies
• IDS/IPS: Signature updates/False-positive handling

3.2 VPN Technologies

• IPsec VPN: IKE phases/ESP encryption modes
• SSL VPN: Clientless vs. Thin-client modes

4. Quality of Service (QoS)

• Key Mechanisms:
  • Classification & Marking (DSCP/802.1p)
  • Queuing Techniques (LLQ/CBWFQ)

5. Automation and Programming

5.1 Programming Skills

• Python Scripting: Netmiko (batch device configuration)
• API Integration: RESTful interface development

5.2 Automation Tools

• Ansible: Playbook authoring (YAML syntax)
• Chef/Puppet: Declarative resource management

6. Wireless & Data Center

6.1 Wireless Networking

• RF Management: Channel planning/Power adjustment
• WLC Configuration: CAPWAP tunnel establishment

6.2 Data Centers

• Virtualization: vSphere clusters/DRS migration
• Storage Networks: iSCSI vs. FC protocol comparison

7. Network Design

• Design Principles:
  • Redundancy architectures (HSRP/VRRP)
  • Hierarchical models (Core/Distribution/Access)

8. Troubleshooting

• Methodologies:
  • Layered diagnostics (Physical → Application layer)
  • Toolchain: Wireshark/NetFlow

9. Emerging Technologies

9.1 SDN

• Core Architecture: Control/Data plane separation
• OpenFlow: Flow table matching rules

9.2 IoT

• Security Challenges: Device authentication (802.1x)
• Protocol Stack: CoAP vs. MQTT comparison