4A0-D01 Exam Dumps : Nokia Data Center Fabric Fundamentals Exam

Comprehensive and Detailed Explanation From Exact Extract:

Option A: TRUE – Only one management interface (mgmt0) exists.

"The system supports a single management interface (mgmt0) for out-of-band access."

— SR Linux Interface Guide, "Management Port"

Option B: TRUE – Network interfaces bind to hardware ports.

"Network interfaces (e.g., ethernet-1/1) map directly to physical line card ports."

— SR Linux Interface Guide, "Port Mapping"

Option C: FALSE – Loopback interfaces are virtual, not physical.

"Loopback interfaces (e.g., lo0) are logical entities with no physical hardware association."

— SR Linux Routing Guide, "Loopback Interfaces"

Option D: TRUE – L2 parameters (e.g., MTU) are set at the main interface; L3 (e.g., IP) at subinterfaces.

"Layer 2 attributes (MTU, admin-state) are configured under the main interface. Layer 3 settings (IP, VRF) are applied to subinterfaces."

— SR Linux Interface Guide, "Subinterface Configuration"

Comprehensive and Detailed Explanation with Exact Extracts:

Option A & B are FALSE: While recursive lookups are required for both next-hops (10.1.1.0 and 10.2.1.0), there is no dependency between them. Each next-hop must be resolved independently via a separate recursive lookup in the routing table. Neither next-hop is resolved "using" the other.

Extract from Nokia SR Linux Configuration Guide (Section: Static Routes):

"An indirect next-hop is not directly connected. The system must perform a recursive lookup in the routing table to find a route that matches the indirect next-hop IP address and resolve it to a directly attached next-hop and egress interface. Each indirect next-hop in a route is resolved independently."

Extract from Nokia SR Linux Fundamentals Guide (Section: Route Resolution):

"Routes with indirect next-hops require recursive route lookup. The router searches its routing table for a path to the indirect next-hop IP address itself. Multiple indirect next-hops in a single route entry are resolved in parallel, not sequentially."

Option C is TRUE: The exhibit shows a single static route (192.168.20.0/30) with two indirect next-hops (10.1.1.0 and 10.2.1.0). This configuration defines a next-hop group with two members for this route, enabling Equal-Cost Multi-Path (ECMP) load balancing or redundancy.

Extract from Nokia SR Linux Configuration Guide (Section: Static Routes):

"Multiple next-hop addresses can be specified for a static route. This creates a next-hop group. Traffic matching the route prefix is load-balanced across all active next-hops in the group using ECMP."

Extract from Nokia SR Linux Fundamentals Guide (Section: Static Routing):

"A static route entry listing multiple next-hops implies a next-hop group. The number of next-hops listed in the show route-table output for a single route ID directly indicates the number of next-hops configured in the group."

Option D is FALSE: The preference value (Pref) is configured per route, not per next-hop within the route. Both next-hops (10.1.1.0 and 10.2.1.0) share the same preference value (5), as they belong to the same route entry (ID 0). Next-hop selection within the group is based on the ECMP hashing algorithm, not preference. Preference is used to choose between different routes (from different protocols) to the same prefix.

Extract from Nokia SR Linux Configuration Guide (Section: Static Routes):

"The preference value is a property of the static route itself, not individual next-hops within it. All next-hops in a static route's next-hop group inherit the same preference value."

Extract from Nokia SR Linux Fundamentals Guide (Section: Route Selection):

"When multiple next-hops exist for a route (ECMP), the active next-hop for a specific flow is determined by a hash of packet header fields (e.g., 5-tuple). Preference values are only compared when selecting between different routes (e.g., static vs. BGP) to the same prefix."

Comprehensive and Detailed Explanation with Exact Extracts:

Option A (TRUE): Type 1 routes enable multi-homing functions.

Extract from Nokia EVPN Multi-Homing Guide:

"Type 1 Ethernet A-D routes signal reachability for an Ethernet Segment (ES) and enable fast convergence/aliasing in multi-homing."

Option B (TRUE): Type 4 routes facilitate DF election.

Extract from Nokia EVPN Fundamentals Guide:

"Type 4 Ethernet Segment routes advertise ESI and VTEP IP to peers for Designated Forwarder (DF) election, which prevents BUM traffic loops."

Option C (FALSE): The ESI is globally unique, not locally significant.

Extract from Nokia SR Linux Configuration Guide (Section: EVPN ESI):

"The ESI must be unique network-wide and consistently configured on all leafs attached to the same multi-homed device. It is not locally significant."

Option D (TRUE): An ES defines the host connectivity model.

Extract from Nokia EVPN Multi-Homing Guide:

"An Ethernet Segment (ES) is a set of links connecting a single host (e.g., server) to one or more leafs for redundancy/load balancing."