Select Two (Multi-Select) Questions

Adjusting the local preference attribute on incoming EBGP updates.

Why wrong: Local preference is an IBGP attribute and is ignored or overwritten on incoming EBGP updates by default.

Changing the local router's weight attribute for incoming EBGP routes.

Why wrong: Weight is strictly local to the router and has no impact on external peers' decisions.

Dynamically altering the BGP session TCP handshake port numbers.

Why wrong: BGP uses port 179 and policies do not alter TCP port numbers.

Adjusting the BGP keepalive timer values dynamically via policy match actions.

Why wrong: Timers are configured under BGP group or neighbor parameters, not routing policies.

Manually assigning physical interface MTU sizes for BGP sessions.

Why wrong: MTU is configured under interface settings, not BGP routing policies.

Standard OSPF Non-backbone Area

Why wrong: Standard areas use Type-5 LSAs.

Standard OSPF Backbone Area (Area 0)

Why wrong: Backbone area uses Type-5 LSAs for external routes, not Type-7.

OSPF Stub Area

Why wrong: Stub areas block external and Type-7 LSAs entirely.

Interface MTU size

Why wrong: While MTU mismatch can cause issues in some implementations if strict-mtu is enabled, it is not one of the fundamental mandatory database synchronization checks like Area ID or timers (though Junos ignores MTU by default unless configured).

Interface primary IP address subnet

Why wrong: OSPF can form unnumbered or secondary IP adjacencies depending on configuration, though primary subnets usually match. The core required match parameters are Area ID, timers, and authentication.

Behavior aggregate classifiers must be disabled on all egress interfaces

Why wrong: BA classifiers are on ingress and unrelated to priority scheduling.

Buffer sizes must be set to zero for all priority queues

Why wrong: Buffers are still required for bursts.

The scheduler must have a transmit-rate percentage of exactly 100%

Why wrong: transmit-rate is not required to be 100% for priority queues.

vlan-id

Why wrong: vlan-id modifies VLAN tags, not CoS bits.

mpls-ttl

Why wrong: mpls-ttl modifies Time To Live, not CoS.

Cluster List length

Why wrong: Cluster list length is not a primary attribute in standard BGP route selection.

Originator ID value

Why wrong: Originator ID is used for loop prevention, not as a primary path selection metric.

Drop profiles are configured under the forwarding-classes hierarchy

Why wrong: Drop profiles are configured under [edit class-of-service drop-profiles].

Drop profiles drop 100% of packets immediately once the queue fill level reaches the start point

Why wrong: Drop probability increases gradually, not instantly to 100% at the start point.

Drop profiles operate exclusively on Layer 2 control frames

Why wrong: Drop profiles apply to scheduled queues containing general IP/MPLS traffic.

Clients of a route reflector must be configured in a full iBGP mesh with each other.

Why wrong: Clients do not need to peer with each other; they only need a BGP session with the route reflector.

Route reflectors automatically modify the AS_PATH attribute of all reflected routes.

Why wrong: Route reflectors do not alter the AS_PATH attribute when reflecting routes.

local-only

Why wrong: local-only is not a standard community keyword.

transit-only

Why wrong: transit-only is not a standard well-known community.

no-peer

Why wrong: no-peer is not a standard community.

They rewrite the AS path length attribute for all reflected client routes.

Why wrong: Route reflectors do not modify AS paths.

They replace the underlying IGP entirely for packet forwarding.

Why wrong: IGP is still required for next-hop resolution.

They operate exclusively at Layer 2 switching boundaries.

Why wrong: BGP operates at Layer 3.

COMMUNITIES

Why wrong: COMMUNITIES is an optional transitive attribute.

MULTI_EXIT_DISC

Why wrong: MULTI_EXIT_DISC (MED) is an optional non-transitive attribute.

LOCAL_PREF

Why wrong: LOCAL_PREF is a well-known discretionary attribute.

MED (Multi-Exit Discriminator)

Why wrong: MED is an optional non-transitive attribute by default.

ORIGINATOR_ID

Why wrong: ORIGINATOR_ID is a non-transitive attribute used within route reflection topologies.

LOCAL_PREF

Why wrong: LOCAL_PREF is restricted to the local autonomous system and is non-transitive to EBGP peers.

LOCAL_WEIGHT

Why wrong: Weight is a Cisco-proprietary local attribute, not a standard BGP path attribute.

NEXT_HOP_OVERRIDE

Why wrong: Next-hop override is a configuration feature on interfaces/VPNs, not a BGP path attribute.

tcp-port

Why wrong: tcp-port is matched via firewall filters for multi-field classification, not as a standalone classifier type name.

mac-address

Why wrong: mac-address is not a CoS classifier type.

Policers buffer exceeding packets in temporal memory queues until transmission capacity opens

Why wrong: Policers drop or mark packets immediately; they do not buffer traffic like shapers.

Policers are always applied to egress interfaces only

Why wrong: Policers are primarily applied on ingress interfaces, though egress policing is also supported on some platforms.

Policers guarantee a minimum bandwidth allocation for best-effort traffic

Why wrong: Guarantees are provided by schedulers, not policers.

dynamic-profiles

Why wrong: Dynamic profiles are used for subscriber management.

bgp-routes

Why wrong: BGP routes handle network reachability, not CoS.

quarantine

Why wrong: Quarantine is not a direct action keyword for MAC limit in Junos.

reboot

Why wrong: Switches never reboot due to MAC limit violations.

isolate-vlan

Why wrong: VLAN migration is not a MAC limit violation action.

Layer 2 Protocol Tunneling (L2PT) is automatically enabled for all protocols without additional configuration when QinQ is active.

Why wrong: L2PT must be explicitly configured on customer-facing access/tunnel ports to process and tunnel control traffic like BPDUs or CDP.

QinQ tunneling requires standard access mode encapsulation on all core-facing uplink ports.

Why wrong: Core-facing uplink ports typically use trunk mode encapsulation carrying the stacked provider VLANs.

rewrite-rule

Why wrong: rewrite-rule is configured under interface settings.

bandwidth-limit

Why wrong: bandwidth-limit is a policer parameter.

policer-action

Why wrong: policer-action belongs to firewall policers.