You are configuring an aggregate route. In this scenario, which two statements are correct? (Choose two.)
Correct Answer:
BC
When configuring anaggregate route, you have options for how to handle traffic that matches the route but
does not match any more specific route in the routing table. Two actions can be taken:discardandreject.
Step-by-Step Breakdown:
Discard:
Thediscardoption will silently drop packets that match the aggregate route. No notification is
sent to the sender, and the packet is simply dropped.
Reject:
Therejectoption will drop the packet and also send anICMP Destination Unreachablemessage
back to the sender. This informs the sender that the packet could not be delivered because there is
no specific route available.
Juniper Reference:
Aggregate Routes: The reject and discard next-hop options provide different levels of feedback when
packets cannot be routed, and they can be used to control how unreachable destinations are handled.
Layer 2 interfaces operate in which two modes? (Choose two.)
Correct Answer:
AC
Comprehensive Detailed Step by Step Explanation with all Juniper Data Center References
Layer 2 interfaces on a switch operate in two key modes:AccessandTrunk.
Step-by-Step Breakdown:
Access Mode:
Access portsare used to connect end devices, like PCs or servers, and they are assigned to a single VLAN. These interfaces handle untagged traffic and do not pass VLAN tags.
Example: A port assigned to VLAN 10 will only handle traffic for that VLAN.
Trunk Mode:
Trunk portsare used to connect switches or other networking devices that need to handle traffic from multiple VLANs. Trunk interfaces carry tagged traffic, allowing multiple VLANs to traverse the same physical link.
Trunk ports typically use802.1QVLAN tagging to differentiate between VLANs.
Juniper Reference:
Access and Trunk Ports: Juniper switches use these modes to manage VLAN traffic at Layer 2, with access ports handling untagged traffic and trunk ports handling tagged traffic from multiple VLANs.
Which two statements about IBGP are correct? (Choose two.)
Correct Answer:
CD
IBGP (Internal Border Gateway Protocol)is used to exchange routing information betweenrouters within the same AS (Autonomous System).
Step-by-Step Breakdown: 
TTL of 255: By default, IBGP sessions are established with aTTL (Time to Live)value of255. This allows IBGP neighbors to communicate over multiple hops within the AS without requiring any additional configuration. Full Mesh Requirement: IBGP requires alogical full meshbetween all IBGP routers to ensure that routing information is fully distributed within the AS. Since IBGP does not propagate routes learned from one IBGP peer to another by default, a full mesh topology is needed unlessroute reflectorsorBGP confederationsare used.
Juniper Reference: IBGP Full Mesh: Juniper recommends using route reflectors in large networks to simplify IBGP full- mesh requirements.
When a MAC limiting violation occurs, the switch performs which two actions by default? (Choose two.)
Correct Answer:
CD
When aMAC limiting violationoccurs on a Juniper switch, the switch will perform the following actions by default:
Step-by-Step Breakdown:
Port Disabled:When the number of MAC addresses on an interface exceeds the configured limit, the port isautomatically disabledto prevent further violations. This is a protective mechanism to prevent MAC address flooding.
Packet Dropped:Additionally, packets from the violating MAC address aredroppedto prevent any further communication from that address. This ensures that only valid MAC addresses are allowed to communicate through the interface. Example Configuration:
set ethernet-switching-options secure-access-port interface If more than five MAC addresses are learned, the port is disabled, and excess packets are dropped.
Juniper Reference: MAC Limiting: When the switch detects a MAC limiting violation, it disables the port and drops further packets from the violating MAC addresses to maintain network security.
Which three actions are required to implement filter-based forwarding? (Choose three.)
Correct Answer:
ACE
Filter-Based Forwarding (FBF) in Junos OS allows traffic to be routed based on specific criteria such as source address, rather than just the destination address. This is useful in scenarios like policy routing or providing multiple paths for different types of traffic.
Step-by-Step Breakdown:
Instance-Type Forwarding:You must create aninstance-type forwardingrouting instance. This routing instance allows for different routing tables based on the incoming packet filter. Command:
set routing-instances FBF-instance instance-type forwarding
Match Filter:You need to create afilterto match the traffic that will be forwarded according to your custom routing policy. This filter is applied to an interface to determine which traffic will use the custom forwarding instance. Command Example:
set firewall family inet filter FBF-filter term 1 from source-address
set firewall family inet filter FBF-filter term 1 then routing-instance FBF-instance RIB Group:ARIB (Routing Information Base) groupis necessary to share routes between the primary routing table and the custom routing instance. This allows FBF traffic to use the routing information from other routing tables. Command Example:
set routing-options rib-groups FBF-group import-rib inet.0
set routing-instances FBF-instance routing-options rib-group FBF-group
Juniper Reference: FBF Configuration: Filter-based forwarding requires these specific steps to redirect traffic to a custom routing table based on filter criteria.
