JN0-650 Exam Dumps - Enterprise Routing and Switching - Professional (JNCIP-ENT)

The exhibit shows a BGP routing process where an Import Policy is being applied to routes received in the RIB-IN. Specifically, Policy 1 states: " Reject 0.0.0.0/0 from AS 64512. "

In Junos OS, when a routing policy rejects a route, that route is not placed in the main routing table (inet.0) for active use. Instead, it becomes a hidden route. To verify that a specific peer is actually sending a route that is subsequently being rejected by your policy, you must use specific diagnostic commands:

Understanding " Hidden " Routes: When a BGP route is received but fails to meet policy requirements (or has an unreachable next-hop), Junos keeps it in the BGP RIB-IN but marks it as " hidden. " It will not appear in a standard show route command.

Command Logic (Option D): The command show route receive-protocol bgp < peer ip > hidden allows an administrator to view all routes received from a specific neighbor, including those that were rejected by import policies.

show route receive-protocol bgp < peer ip > : Shows only the routes that passed the import policy and were accepted into the table. Since the 0.0.0.0/0 route from AS 64512 is explicitly rejected in the exhibit, it would not show up here.

Adding the hidden keyword is the essential step to see the rejected default route and verify that AS 64512 is indeed sending it before the policy drops it.

Other Options:

Option A is incorrect because it only shows accepted routes.

Option B and C are used to filter the existing active routing table based on gateway or next-hop attributes, but they cannot show routes that have been rejected and excluded from that table.

Private VLANs (PVLANs) allow for granular port isolation within a single broadcast domain. When extending a PVLAN across multiple switches (S1 to S2), the secondary VLANs (Community or Isolated) must be preserved across the trunk links.

802.1Q Tagging (Option B): For traffic from a Community VLAN (RND) to reach members on a different switch, the Community VLAN must have its own 802.1Q VLAN tag (VLAN ID) associated with it. When a frame from a community port on S1 traverses the trunk to S2, it is tagged with this specific secondary VLAN ID. S2 receives the tagged frame, identifies it as belonging to the RND community, and forwards it to the appropriate community or promiscuous ports.

Why it fails without a tag: If the RND community is only defined locally on S1 without a global VLAN ID, the trunk port will not know how to distinguish that traffic from the Primary VLAN or other communities.

Incorrect Options: Option A is incorrect because the community VLAN must have a different tag than the parent (Primary) VLAN to maintain the internal PVLAN logic. Option C is incorrect because stripping tags would lead to the traffic being merged into the native VLAN or dropped. Option D is incorrect because RND is a community VLAN; changing it to an isolated VLAN would change its behavior (preventing communication between members of that same group).

In OSPF, the election of a Designated Router (DR) and a Backup Designated Router (BDR) is mandatory on broadcast and non-broadcast multi-access (NBMA) network types to manage link-state database synchronization efficiently.

The exhibit shows that both device1 and device2 have their OSPF interface priority explicitly set to 0. According to the Junos OS 24.4 OSPF implementation:

Ineligibility (Priority 0): A router with a priority of 0 is strictly ineligible to be elected as a DR or BDR for that segment.

No Election Possible: When every router on a broadcast segment has a priority of 0, the election process cannot complete because there are no eligible candidates to fill the required roles.

State Behavior (Stuck in 2-Way): In OSPF adjacency formation, the 2-Way state indicates that bidirectional communication has been established (each router has seen itself in the other ' s Hello packets). However, to progress to the Exstart and Exchange states on a multi-access network, routers must first identify a DR and BDR.

Result: Since neither router can become the DR, they both wait indefinitely for a third party (with priority > 0) to take the lead. Consequently, the OSPF adjacency will be stuck in the 2-Way state. Adjacencies only reach the Full state with the DR and BDR; routers in a " DROther " role remain in 2-Way with each other.

Option A and D are incorrect because the router ID (IP address) only acts as a tiebreaker if priorities are equal and greater than 0. Option B is incorrect because routers cannot reach the Exstart state (where they negotiate master/slave for database exchange) without first having a DR/BDR elected.

In an EVPN-VXLAN environment, different BGP route types serve distinct purposes in building the control plane. The Ethernet Segment Identifier (ESI) is a unique 10-byte identifier used to represent a multi-homed segment.

Type 1: Ethernet Auto-Discovery (A-D) Route (Option A): This route type is essential for multi-homing scenarios. It carries the ESI to support features like fast convergence and aliasing. By advertising an A-D route per Ethernet Segment, a PE tells other routers that it is connected to that specific ESI. It does not carry individual host MAC addresses; instead, it provides a " mass withdraw " mechanism to quickly update paths if the entire segment goes down.

Type 4: Ethernet Segment Route (Option D): This route is used exclusively for Designated Forwarder (DF) election. It advertises the existence of an ESI and the ES-Import Route Target to all other PE routers. This allows PE routers connected to the same multi-homed segment to discover each other automatically and elect a DF to handle BUM traffic. Like Type 1, it focuses on the segment identity and does not include MAC addresses.

Type 2: MAC/IP Advertisement Route (Option B): This is the primary route used for host reachability. It must include a MAC address (and optionally an IP). While it also includes the ESI to indicate which segment the host is behind, its primary function is MAC advertisement.

Type 3: Inclusive Multicast Ethernet Tag Route (Option C): This route is used for VTEP discovery and building the replication list for BUM traffic. It identifies the VTEP ' s IP and the VNI, but it does not carry the ESI or MAC addresses.

When 802.1X server fail fallback is enabled with the vlan-name feature, the switch provides a specific survival mechanism for both existing and new sessions when the RADIUS server becomes unreachable.

Existing Clients (Statement B): Clients that have already successfully authenticated are unaffected by the server ' s unavailability in the short term. They maintain their current network access until their specific re-authentication timer expires. Only then will the switch attempt to contact the server again and trigger the fallback action if the server remains down.

New Clients (Statement D): For any new device attempting to connect while the RADIUS server is down, the switch cannot perform a standard authentication. Under the vlan-name fallback configuration, these new clients are automatically placed into the specified fallback VLAN and granted access based on the local policy defined for that VLAN.

Why others are incorrect: Statement A is incorrect because disconnecting active users would cause unnecessary service disruption. Statement C is incorrect because new clients cannot " request " a VLAN during the 802.1X handshake; the switch assigns it based on the fallback configuration.