SP Network Infrastructure and Protocols 1 — Questions and Answers
Question 1: Which protocol is used by service providers to dynamically exchange routing information between autonomous systems?
- OSPF
- EIGRP
- BGP (Correct answer)
- RIP
Correct answer: BGP
Border Gateway Protocol (BGP) is the standard inter-domain routing protocol used between service provider autonomous systems on the internet.
Question 2: What technology do service providers use to forward packets based on labels rather than IP addresses?
- VLANs
- MPLS (Correct answer)
- NAT
- DHCP
Correct answer: MPLS
Multiprotocol Label Switching (MPLS) enables service providers to forward packets using short label values, improving speed and enabling traffic engineering.
Question 3: In a service provider network, what is the role of a Provider Edge (PE) router?
- Connects the provider's core routers to each other
- Connects the provider network to customer sites via CE routers (Correct answer)
- Manages DNS records for customers
- Acts as a firewall at the network perimeter
Correct answer: Connects the provider network to customer sites via CE routers
A Provider Edge (PE) router sits at the boundary between the service provider network and customer CE routers, handling MPLS VPN label operations.
Question 4: What does QoS stand for and why is it critical in service provider networks?
- Quality of Service — prioritizes traffic to meet performance SLAs (Correct answer)
- Quantity of Switches — counts active network devices
- Queue of Sessions — tracks concurrent user sessions
- Quality of Security — enforces firewall rules
Correct answer: Quality of Service — prioritizes traffic to meet performance SLAs
Quality of Service (QoS) allows service providers to prioritize latency-sensitive traffic like voice and video to ensure SLA performance commitments are met.
Question 5: Which protocol automatically assigns IP addresses to devices in a service provider managed network?
- DNS
- SNMP
- DHCP (Correct answer)
- RADIUS
Correct answer: DHCP
Dynamic Host Configuration Protocol (DHCP) automatically assigns IP addresses, subnet masks, gateways, and DNS servers to network devices.
Question 6: What is the purpose of Anycast routing used by large service providers?
- Send one packet to all hosts simultaneously
- Route traffic to the nearest or best-performing instance of a service (Correct answer)
- Encrypt routing table updates
- Assign static IPs to all servers
Correct answer: Route traffic to the nearest or best-performing instance of a service
Anycast allows multiple servers to share the same IP address and routes incoming requests to the topologically nearest instance, reducing latency.
SP Network Infrastructure and Protocols 1
Which protocol is used by service providers to dynamically exchange routing information between autonomous systems?