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."

Comprehensive and Detailed Explanation with Exact Extracts:

Option A is FALSE: SR Linux does not use a simple modulo operation for ECMP hashing. Modulo can lead to uneven distribution and poor resilience. Instead, it uses a more advanced hash algorithm (like CRC32 or murmur) applied to packet header fields (e.g., 5-tuple).

Extract from Nokia SR Linux Configuration Guide (Section: ECMP Configuration):

"The system uses a hash algorithm (e.g., crc32, murmur) over selected fields in the packet header (such as source/destination IP, protocol, source/destination port) to determine the next-hop path. A modulo operation on the hash result relative to the number of paths is not the primary method; the hash space is designed for better spread and minimal disruption."

Option B is FALSE: Resilient ECMP aims for the opposite behavior. Using the same hash seed across routers ensures that a flow taking a specific path on one router will likely take the same corresponding path on downstream routers ("flow stickiness"), preventing localized congestion. Hash buckets map flows to paths consistently network-wide.

Extract from Nokia SR Linux Fundamentals Guide (Section: Resilient Hashing):

"Consistent hash seeds across all routers in the network are critical for resilient ECMP. This ensures that flows hashing to a particular path on an upstream router will hash to the same logical path on downstream routers, maintaining overall traffic distribution and preventing hot-spots."

Option C is FALSE: Using different hash seeds on downstream routers would cause flows following the same path upstream to be randomly distributed downstream, creating potential congestion points ("polarization"). Resilient ECMP requires the same hash seed to be configured consistently across the network for predictable, stable, and congestion-free flow paths.

Extract from Nokia SR Linux Configuration Guide (Section: ECMP Resilient Hashing):

"The hash-seed parameter must be configured identically on all routers within a domain utilizing resilient ECMP. Different seeds cause flow polarization on downstream nodes, defeating the purpose of resilient load balancing and potentially causing link congestion."

Option D is TRUE: This is the core principle of resilient hashing (also called consistent hashing). When a next-hop fails, the hash mapping is recalculated. Only flows that were previously mapped to the failed next-hop need to be remapped to the remaining healthy next-hops. Flows originally mapped to healthy next-hops remain entirely unaffected.

Extract from Nokia SR Linux Fundamentals Guide (Section: Resilient Hashing Benefits):

"A key advantage of resilient hashing is minimal disruption during next-hop failures. When a single next-hop becomes unavailable, only the flows that were hashed to that specific next-hop are affected and need to be rehashed among the remaining next-hops. Flows assigned to other next-hops continue to use their original paths without interruption."

Extract from Nokia SR Linux Configuration Guide (Section: ECMP Resilient Hashing):

"Resilient hashing minimizes the number of flows that need to change paths when the set of next-hops changes (due to failure or addition). This provides greater stability compared to traditional modulo-based hashing, where a topology change can impact a large portion of flows."

Comprehensive and Detailed Explanation with Exact Extracts:

Options A, B, and C are part of ZTP autoboot:

A: DHCP assigns IP/gateway.

B/C: Scripts download images/RPMs from servers (HTTP/FTP).

Extract from Nokia SR Linux ZTP Guide:

"Autoboot triggers DHCP discovery for IP/gateway. The device then fetches a provisioning script (via DHCP/DNS) that downloads RPMs/images from HTTP/FTP servers."

Option D is NOT part of ZTP autoboot:

Fabric Services System (FSS) and its digital sandbox are separate tools for lifecycle management. ZTP does not auto-deploy them.

Extract from Nokia FSS Deployment Guide:

"FSS deployment requires manual setup or orchestration tools. The digital sandbox is not automatically deployed via ZTP autoboot."

Comprehensive and Detailed Explanation with Exact Extracts:

Option B is FALSE:

The system-cpu-policer is a software-based policer running on the CPM CPU, not hardware-based.

Extract from Nokia SR Linux QoS Guide (Section: Control Plane Policing):

"The system-cpu-policer is enforced in software on the CPM. In contrast, distributed-policers are hardware-based and execute on line cards."

Other Options are TRUE:

A: Hierarchical policing (e.g., per-protocol child policers under an aggregate) is supported.

Extract: "Hierarchical policers allow aggregate rate-limiting plus per-protocol sub-policers (e.g., for BGP, OSPF)."

C: The system-cpu-policer polices the aggregate traffic reaching the CPM.

Extract: "system-cpu-policer applies to the sum of all traffic forwarded from line cards to the CPM."

D: CPM-filter entries can combine both policers:

distributed-policer (line card hardware) for early per-card rate-limiting.

system-cpu-policer (CPM software) for final aggregate policing.

Extract: "CPM-filter entries may reference both a distributed-policer (for per-line card enforcement) and a system-cpu-policer (for CPM-wide aggregation)."

Comprehensive and Detailed Explanation From Exact Extract:

Option A is TRUE: SR Linux is fully model-driven.

"Every configuration and state element in SR Linux is defined by a YANG model."

— SR Linux YANG Data Modeling Guide, "Introduction"

Option B is FALSE: Containers are branches (grouping nodes), and leafs are data components (terminal values). The description is reversed.

"YANG structures data hierarchically: containers organize child nodes (branches), while leafs hold actual data values (e.g., integers, strings)."

— SR Linux YANG Data Modeling Guide, "Tree Structure"

Option C is TRUE: YANG supports JSON/XML encoding.

"YANG models serialize natively to XML or JSON for machine-to-machine communication."

— SR Linux gNMI and JSON-RPC Guide, "Data Encoding"

Option D is TRUE: YANG enables standardized access via gNMI/NETCONF.

"YANG provides a consistent schema for applications to retrieve/configurate data via protocols like gNMI."

— SR Linux Automation Guide, "Model-Driven Interfaces"

Comprehensive and Detailed Explanation with Exact Extracts:

Exhibit Analysis:

The configuration defines a log file named bgp-log (not a buffer) under system logging.

It includes messages from subsystems bgp and netinst (network-instance).

SR Linux Logging Command Syntax:

show system logging file  is the operational command to display contents of a log file.

show system logging buffer  is used for memory buffers, not files.

info commands display configuration, not log contents.

Verification from Documentation:Extract from Nokia SR Linux CLI Guide (Section: Logging Commands):

"Use show system logging file  to display the current contents of a configured log file. For example:

text

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A:dc-leaf-1# show system logging file bgp-log

This outputs the log entries stored in the specified file."

Extract from Nokia SR Linux Configuration Guide (Section: Log Files):

"Log files are persistent entities stored in /var/log/srlinux/. Their contents are viewed exclusively via show system logging file, not info or buffer commands."

Why Other Options Are Incorrect:

A: buffer references in-memory logs, not persistent files.

C/D: info displays configuration (e.g., info system logging shows the snippet in the exhibit), not log contents.

Comprehensive and Detailed Explanation:

LLDP (Link Layer Discovery Protocol) frames are link-local multicast frames sent to the destination MAC address 01:80:C2:00:00:0E. They are not routed (eliminating Option D) and operate independently of VRF tables (eliminating Options A/B). SR Linux floods LLDP frames periodically on all active interfaces.

Exact Extract:

*"LLDP frames are transmitted periodically as untagged Ethernet frames to the nearest-bridge multicast address (01:80:C2:00:00:0E). They are flooded locally and not forwarded beyond the local subnet."*