OSI Challenge
A PC has link lights and can communicate locally, but cannot reach another subnet. Which OSI layer should you investigate first?
Layer 3 – Network.
A PC knows the IPv4 address of a device on its LAN but needs its hardware address. Which protocol is involved?
ARP
A company needs administrators to configure individual switch ports, VLANs, and other settings. What type of switch is required?
Managed switch.
A cable must run near equipment producing significant electromagnetic interference. Which medium would best avoid EMI/RFI?
Fiber optic.
A Windows PC can reach its gateway but not a remote server. Which command can show the intermediate hops toward the server?
tracert
A user reaches a server by IP, but the required service will not connect. Which layer should you investigate next?
Layer 4 – Transport; check TCP/UDP and required ports.
A technician uses ping and receives error/diagnostic information about IP communication. Which protocol is involved?
ICMP
A company connects multiple LANs at geographically separated offices. What device and network type are involved?
Router and WAN.
You need a high-speed fiber connection within a building where extreme long-distance capability is unnecessary. Which fiber type is appropriate?
Multimode fiber.
On Ubuntu/Debian, which command refreshes the available package information from configured repositories?
sudo apt update.