JN0-351 Exam Dumps : Enterprise Routing and Switching Specialist (JNCIS-ENT)

• A is correct because when an OSPF adjacency is established, a router will advertise a connected network to OSPF neighbors. An OSPF adjacency is a logical relationship between two routers that agree to exchange routing information using the OSPF protocol1. To establish an OSPF adjacency, the routers must be in the same area, have compatible parameters, and exchange hello packets1. Once an OSPF adjacency is formed, the routers will exchange database description (DBD) packets, which contain summaries of their link-state databases (LSDBs)1. The LSDBs include information about the connected networks and their costs2. Therefore, when an OSPF adjacency is established, a router will advertise a connected network to OSPF neighbors through DBD packets.
• D is correct because when a static route to the 224.0.0.5 address is created, a router will advertise a connected network to OSPF neighbors. The 224.0.0.5 address is the multicast address for all OSPF routers3. A static route to this address can be used to send OSPF hello packets to all OSPF neighbors on a network segment3. This can be useful when the network segment does not support multicast or when the router does not have an IP address on the segment3. When a static route to the 224.0.0.5 address is created, the router will send hello packets to this address and establish OSPF adjacencies with other routers on the segment3. As explained above, once an OSPF adjacency is formed, the router will advertise a connected network to OSPF neighbors through DBD packets.

Junos devices support various types of tunnels for different purposes12.

• Option B is correct. Generic Routing Encapsulation (GRE) is a tunneling protocol that can encapsulate a wide variety of network layer protocols inside virtual point-to-point links over an Internet Protocol network1. Junos devices support GRE tunnels1.
• Option D is correct. IPsec (Internet Protocol Security) is a protocol suite for securing Internet Protocol (IP) communications by authenticating and encrypting each IP packet of a communication session1. Junos devices support IPsec tunnels1.
• Option A is incorrect. Spanning Tree Protocol (STP) is not a type of tunnel. It’s a network protocol designed to prevent loops in a bridged Ethernet local area network2.
• Option C is incorrect. While Junos devices do support IP-IP (also known as IP tunneling), it’s not supported on all Junos devices1.

• C is correct because Layer 2 control traffic is permitted on the secondary link of a redundant trunk group (RTG) on EX Series switches. Layer 2 control traffic includes protocols such as LLDP, LACP, and STP, which are used to exchange information and coordinate actions between switches1. According to the Juniper Networks documentation2, Layer 2 control traffic is allowed to pass through both the active and the secondary links of an RTG, but data traffic is only forwarded through the active link. This allows the switches to maintain their Layer 2 adjacencies and monitor the link status on both links.
• D is correct because if the active link fails, then the secondary link automatically takes over in an RTG on EX Series switches. An RTG consists of two trunk links: an active or primary link, and a secondary or backup link2. The active link is used to forward data traffic, while the secondary link is in standby mode. If the active link fails or becomes unavailable, the secondary link immediately transitions to a forwarding state and takes over the data traffic without waiting for normal STP convergence2. This provides fast recovery and redundancy for the network.