What are two attributes of the UDP protocol? (Choose two.)

1. A. UDP is more reliable than TCP.
2. B. UDP is always slower than TCP.
3. C. UDP is best effort.
4. D. UDP is connectionless.

Correct Answer: CD
UDP (User Datagram Protocol) is known for being connectionless (D) and providing best-effort delivery without the reliability mechanisms present in TCP (C). This means that UDP does not establish a connection before sending data and does not guarantee delivery, order, or error checking, making it faster but less reliable than TCP.

Which two statements about route preference in Junos are correct? (Choose two.)

1. A. Both direct and static routes have the same preference.
2. B. Both direct and local routes have the same preference.
3. C. Both OSPF internal and OSPF AS external routes have the same preference.
4. D. Both EBGP and IBGP routes have the same preference.

Correct Answer: BC
In Junos OS, route preference (also known as administrative distance) is used to determine the preferred route among multiple routes to the same destination learned via different routing protocols. Direct and local routes, which represent directly connected networks and interfaces, typically share the same low preference value, indicating high trustworthiness because they are directly connected to the router. OSPF internal routes (routes within the same OSPF area) and OSPF AS external routes (routes that are external to the OSPF autonomous system but redistributed into OSPF) also share the same preference value, although this value is higher (indicating less trust) than for direct and local routes. This distinction helps the routing engine decide which routes to use when multiple paths are available.

What are two methods for navigating to configuration mode from an operational mode prompt? (Choose two.)

1. A. Use the edit command.
2. B. Use the quit command.
3. C. Use the exit command.
4. D. Use the configure command.

Correct Answer: AD
In Junos OS, to navigate from operational mode to configuration mode, you can use either the edit or configure command. Both commands move the CLI from operational mode, where you can view the state of the device, to configuration mode, where you can make changes to the device's configuration.

Click the Exhibit button.

Referring the exhibit, what does the highlighted number indicate?

1. A. route preference is 5
2. B. hop count is 5
3. C. cost is 5
4. D. metric is 5

Correct Answer: A
In the exhibit shown, the highlighted number next to the route type (Static) within the square brackets indicates the route preference, also known as the administrative distance. In Junos, the route preference is a value that determines the priority of the route source. Lower numbers indicate a higher priority when the routing table is being calculated. The route preference is used to select the best route when multiple paths to the same destination exist from different routing sources. The number 5 is unusually low for a static route by default, suggesting it has been manually configured to override other route types.

Which protocol is responsible for learning an IPv4 neighbor's MAC address?

1. A. Address Resolution Protocol (ARP)
2. B. Network Address Translation (NAT)
3. C. Media Access Control Security (MACsec)
4. D. Neighbor Discovery Protocol (NDP)

Correct Answer: A
The Address Resolution Protocol (ARP) is responsible for mapping an IPv4 address to a machine's MAC address. ARP operates at Layer 2 of the OSI model and is used to find the MAC address of a host given its IPv4 address. When a device wants to communicate with another device on the same local network, it uses ARP to discover the recipient's MAC address.
References:
✑ Juniper official documentation: ARP.
✑ Networking standards: RFC 826.