Scope

Study Guide

I. Network Troubleshooting

1. Troubleshooting methodology (the 6-step process)
2. Command-line tools (ping, traceroute, ipconfig/ifconfig, nslookup, netstat/ss, tcpdump/Wireshark basics)
3. Wireless troubleshooting (signal strength, interference, channel issues, SSID/VLAN mismatches)
4. Cable/connector problems
5. Common performance issues (latency, packet loss, bottlenecks)
6. Device configuration mismatches (routing tables, VLANs, STP)

II. Networking Concepts

1. OSI model (layers/functions, encapsulation)
2. Common ports/protocols/services (memorize 20-25 key ones: HTTP 80, HTTPS 443, DNS 53, DHCP 67/68, SNMP 161/162, RDP 3389, SIP 5060/5061, SSH 22, etc.)
3. IP addressing/subnetting (IPv4/IPv6, CIDR, calculate subnets quickly)
4. Traffic types (unicast/multicast/broadcast/anycast)
5. Cloud basics (IaaS/PaaS/SaaS, public/private/hybrid, VPC, NFV, scalability/elasticity)

III. Network Implementation

1. Switching (VLANs, 802.1Q tagging, STP/RSTP, link aggregation, port configs, native/voice VLAN)
2. Routing (static/dynamic: OSPF/BGP/EIGRP basics, NAT/PAT, route selection via AD/metric/prefix, FHRP like HSRP/VRRP, subinterfaces)
3. Wireless setup (AP modes, channels/frequencies, SSID config)

IV. Network Operations

1. Monitoring (SNMP, Syslog, baselines, performance metrics)
2. Documentation (diagrams, inventories, IPAM)
3. Device management (backups, change management)
4. High availability/disaster recovery basics

V. Network Security

1. Common attacks (DoS, ARP poisoning, spoofing, VLAN hopping)
2. Hardening (port security, disable unused ports, encryption)
3. Authentication (802.1X, RADIUS/TACACS+, MFA, least privilege)
4. Wireless security (WPA3, EAP)
5. Firewall/IDS/IPS basics