2Network Access

Practice questions →Glossary →

2.1VLANs and trunking
Covers VLANs that split one physical switch into multiple broadcast domains, access ports that place an end host into a single VLAN, trunk ports that extend the same VLAN across multiple switches by tagging frames per VLAN with 802.1Q, the native VLAN (the one VLAN sent untagged), and the default VLAN (VLAN 1) that every port belongs to out of the box, all alongside the Cisco IOS configuration and verification commands.
2.2Discovery protocols and EtherChannel
Covers CDP (Cisco-proprietary) and LLDP (industry-standard) for automatically discovering directly connected neighbors, and EtherChannel for bundling multiple physical links into one logical link to gain both bandwidth and redundancy (dynamic negotiation via LACP, L2/L3 configuration, verification with show etherchannel summary), all with the Cisco IOS configuration and verification commands.
2.3STP and RSTP
Covers spanning tree that prevents the broadcast storm of a redundant L2, Cisco's default Rapid PVST+ (per-VLAN RSTP), root bridge election decided by the bridge ID, port roles (root/designated/alternate) and states (discarding/learning/forwarding), and PortFast for end-host ports plus BPDU Guard to defend against rogue BPDUs, all with the Cisco IOS configuration and verification commands.
2.4Cisco wireless architecture
Covers the autonomous architecture that manages each AP individually, the cloud-based architecture that manages them centrally from the cloud, and the split-MAC (WLC) architecture that divides work between a WLC and its APs; the AP modes of a lightweight AP that joins a WLC over CAPWAP; the management-access options for APs/WLCs; and WLAN creation in the WLC GUI (SSID, WPA2 PSK, QoS profile, advanced settings).
2.5Device management access
Covers the paths for managing network devices—the physically attached, out-of-band console; unencrypted Telnet versus encrypted SSH; and the web GUI over HTTP/HTTPS—together with the AAA protocols that centralize their login authentication on an external server: TACACS+ (Cisco-proprietary, TCP 49, separates AAA, encrypts the entire payload) and RADIUS (industry standard, UDP, combines authentication and authorization), all with the Cisco IOS configuration.