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

Option A is correct. Creating multiple areas in OSPF can help to reduce the convergence time . This is because changes in one area do not affect other areas, so fewer routers need to run the SPF algorithm in response to a change.

Option D is correct. Creating multiple areas in OSPF can help to reduce Link State Advertisement (LSA) flooding across the network. This is because LSAs are not flooded out of their area of origin.

The exhibit shows the configuration of RSTP on EX-4, which has the command  force-version stp .  This command forces the switch to use the legacy STP protocol instead of RSTP, even though the switch supports RSTP 1 .  This means that EX-4 will not be able to take advantage of the faster convergence and enhanced features of RSTP, such as edge ports, link type, and proposal/agreement sequence 2 .

The other switches in the network are likely to be running RSTP, as it is the default protocol for EX Series switches 3 . Therefore, there will be a compatibility issue between EX-4 and the other switches, which will result in longer convergence times and suboptimal performance.  The switch will also generate a warning message that says “Warning: STP version mismatch with neighbor” when it receives a BPDU from a RSTP neighbor 1 .

To solve this problem, the force-version command must be removed from EX-4, so that it can run RSTP natively and interoperate with the other switches in the network. This will enable faster convergence and better stability for the network topology.  To remove the command, you can use the  delete protocols rstp force-version  command in configuration mode 1 .

According to the Juniper documentation1, a native VLAN is a VLAN that carries untagged traffic on a trunk port. A Wi-Fi access point may need a native VLAN to associate untagged traffic with a specific VLAN, such as the management VLAN. On Juniper EX Series switches, you can enable a native VLAN on a switch port by setting the interface-mode to trunk and specifying a native-vlan-id. For example, the following configuration enables a native VLAN with ID 1 on the switch port ge-0/0/12:

set interfaces ge-0/0/1 unit 0 family ethernet-switching interface-mode trunk

set interfaces ge-0/0/1 unit 0 family ethernet-switching vlan members all

set interfaces ge-0/0/1 unit 0 family ethernet-switching native-vlan-id 1

The other options are not correct because they do not address the requirement of untagged traffic. VLAN tagging is the process of adding a VLAN identifier to a frame, which is not needed for untagged traffic. Flexible VLAN tagging is a feature that allows multiple VLAN tags on a single interface, which is not relevant for this scenario. Voice VLAN is a feature that allows voice traffic to be separated from data traffic on a switch port, which is not related to untagged traffic or Wi-Fi access points. References: Understanding Native VLANs on Trunks | Junos OS, Configuring a Native VLAN on a Trunk Port | Junos OS