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Arista ACE-S Campus study materials
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Arista ACE-S Campus practice questions

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Question 1Campus Networking Fundamentals

Which IEEE standard defines Power over Ethernet as used to power access points and IP phones from a campus switch port?

  1. IEEE 802.3af Correct answer.
  2. IEEE 802.1Q
  3. IEEE 802.3ad
  4. IEEE 802.1X

Explanation

Power over Ethernet is standardized in the IEEE 802.3af (and later 802.3at/802.3bt) amendments, which define how DC power is delivered over twisted-pair cabling alongside data. The other standards listed address VLAN tagging, link aggregation, and port-based authentication.

Question 2Campus Networking Fundamentals

In a campus design, what is the primary role of the access layer?

  1. Aggregating distribution switches into a routed core
  2. Hosting the default gateway for all campus VLANs
  3. Providing WAN edge connectivity to service providers
  4. Connecting end devices such as PCs, phones, and APs to the network Correct answer.

Explanation

The access layer is where endpoint devices attach, typically via edge switches that provide port density, PoE, and VLAN segmentation. Aggregation, WAN edge, and gateway functions belong to higher layers of the hierarchy.

Question 3Campus Networking Fundamentals

Which protocol allows a host to dynamically learn its IPv4 address, subnet mask, and default gateway from a server?

  1. DHCP Correct answer.
  2. ARP
  3. DNS
  4. SNMP

Explanation

DHCP supplies IP configuration parameters to clients automatically through a lease process. DNS resolves names, ARP resolves IP to MAC, and SNMP is used for monitoring and management.

Question 4Campus Networking Fundamentals

What is the purpose of a VLAN in a campus network?

  1. To increase the physical link speed between switches
  2. To logically segment a switched network into separate broadcast domains Correct answer.
  3. To encrypt traffic between switches
  4. To provide redundant paths between switches

Explanation

A VLAN creates a logical Layer 2 partition, so each VLAN is its own broadcast domain regardless of physical topology. Encryption, link speed, and redundancy are handled by other features.

Question 5Campus Networking Fundamentals

Which cable type is typically used for a 10GBASE-SR connection between a campus switch and a nearby distribution switch in the same building?

  1. Cat3 UTP
  2. Multimode fiber Correct answer.
  3. Single-mode fiber
  4. Coaxial cable

Explanation

10GBASE-SR is specified for short-reach multimode fiber, which suits intra-building distances. Single-mode fiber is used for longer reaches, while Cat3 and coax do not support 10G Ethernet.

Question 6Campus Networking Fundamentals

Which Arista feature allows multiple physical switches to be managed and operated as a single logical device?

  1. LLDP
  2. VRRP
  3. STP
  4. MLAG Correct answer.

Explanation

Multi-Chassis Link Aggregation (MLAG) lets two switches act as one logical aggregation endpoint, so downstream devices can form a port-channel across both. VRRP is a gateway redundancy protocol, LLDP is neighbor discovery, and STP prevents Layer 2 loops.

Question 7Campus Networking Fundamentals

What does a switch do when it receives a frame with an unknown destination MAC address?

  1. Sends the frame back out the ingress port
  2. Floods the frame out all ports in the same VLAN except the ingress port Correct answer.
  3. Drops the frame and sends an ICMP unreachable message
  4. Queues the frame until the destination is learned

Explanation

When the destination MAC is not in the MAC address table, the switch floods the frame within the VLAN, excluding the port it arrived on. This ensures delivery while the address is being learned.

Question 8Campus Networking Fundamentals

What is the default administrative distance of a directly connected route on an Arista EOS device?

  1. 1
  2. 90
  3. 110
  4. 0 Correct answer.

Explanation

Directly connected routes have an administrative distance of 0, making them the most preferred source of routing information. Static routes default to 1, EIGRP to 90, and OSPF to 110.

Question 9Campus Networking Fundamentals

A switch port is configured in access mode. Which statement describes its behavior?

  1. It forwards frames only for the native VLAN of the trunk
  2. It blocks all traffic until 802.1X authentication succeeds
  3. It carries multiple VLANs and tags all frames toward the host
  4. It carries traffic for a single VLAN and sends untagged frames to the attached host Correct answer.

Explanation

An access port belongs to one VLAN and presents untagged frames to the connected endpoint, which is typical for PCs and printers. Trunk ports carry multiple VLANs using tags.

Question 10Campus Networking Fundamentals

Two Arista switches are connected by two parallel links that are bundled into a single port-channel. What benefit does this configuration provide?

  1. Removal of the need for VLAN configuration
  2. Automatic IP address assignment to the switches
  3. Guaranteed per-flow packet ordering across all flows
  4. Increased aggregate bandwidth with loop-free redundancy Correct answer.

Explanation

A port-channel treats bundled links as one logical interface, adding bandwidth and providing resilience if a member link fails. Hashing per flow keeps individual flows on one link rather than guaranteeing global ordering.

Question 11Campus Networking Fundamentals

Which protocol should be enabled to prevent a Layer 2 loop when two access switches are accidentally interconnected with redundant links?

  1. OSPF
  2. Spanning Tree Protocol Correct answer.
  3. VRRP
  4. LACP

Explanation

Spanning Tree Protocol detects and blocks redundant Layer 2 paths to prevent broadcast loops. OSPF is a Layer 3 routing protocol, VRRP provides gateway redundancy, and LACP manages link bundles.

Question 12Campus Networking Fundamentals

A network engineer wants to verify that a switch is receiving LLDP advertisements from a directly connected neighbor. Which command is most appropriate on Arista EOS?

  1. show mac address-table
  2. show ip route
  3. show vlan
  4. show lldp neighbors Correct answer.

Explanation

The 'show lldp neighbors' command lists discovered LLDP neighbors, including their port and system details. The other commands display routing, VLAN, or MAC table information.

Question 13Campus Networking Fundamentals

Which statement best describes the role of a distribution layer in a three-tier campus design?

  1. It houses only wireless controllers and no routing functions
  2. It provides direct internet peering to service providers
  3. It aggregates access switches and enforces policy between VLANs Correct answer.
  4. It connects individual end-user devices to the network

Explanation

The distribution layer aggregates access-layer uplinks and commonly hosts inter-VLAN routing and policy enforcement. Connecting endpoints is the access layer's job, and service-provider peering belongs to the edge or core.

Question 14Campus Networking Fundamentals

A host with IP address 10.10.10.50/24 needs to reach 10.10.20.50. What does the host do first?

  1. Sends an ARP request for 10.10.20.50 on the local segment
  2. Sends a DHCP request for a new address on the remote subnet
  3. Sends the frame to its default gateway MAC address Correct answer.
  4. Sends the packet directly to the destination MAC address

Explanation

Because the destination is outside the host's /24 subnet, the host forwards the frame to its default gateway, using ARP to resolve the gateway's MAC if needed. It does not ARP for the remote host directly.

Question 15Campus Networking Fundamentals

What is the primary purpose of a DHCP relay agent on a campus switch?

  1. Forwarding DHCP broadcasts from a client subnet to a DHCP server on another subnet Correct answer.
  2. Encrypting DHCP messages between client and server
  3. Assigning IP addresses locally when the DHCP server is unreachable
  4. Preventing duplicate IP addresses on the local segment

Explanation

A DHCP relay (helper address) converts client broadcasts into unicast packets toward a DHCP server on a different subnet. It does not assign addresses itself or provide encryption.

Question 16Campus Networking Fundamentals

Which statement about a trunk port is accurate?

  1. It can carry multiple VLANs and tags frames so the peer can distinguish them Correct answer.
  2. It is used exclusively for connecting end-user PCs
  3. It always strips tags from all frames before forwarding
  4. It can carry only the native VLAN and drops tagged frames

Explanation

Trunk ports carry multiple VLANs between switches or to devices that understand tagging, using 802.1Q tags to identify VLAN membership. Access ports, not trunk ports, connect typical end-user PCs.

Question 17Campus Networking Fundamentals

Which Arista EOS feature allows a pair of switches to share a virtual IP address as the default gateway for hosts?

  1. VRRP Correct answer.
  2. LACP
  3. STP
  4. LLDP

Explanation

Virtual Router Redundancy Protocol lets two or more routers or switches share a virtual IP, providing a resilient default gateway. LACP bundles links, STP prevents loops, and LLDP discovers neighbors.

Question 18Campus Networking Fundamentals

A campus switch port must deliver power to a wireless access point while also carrying its data traffic. Which combination of features is required?

  1. LLDP disabled and a static MAC configured
  2. STP disabled on the port and a trunk configured
  3. PoE enabled on the port and the port assigned to the correct VLAN Correct answer.
  4. LACP configured on the port and a routed interface assigned

Explanation

PoE supplies power to the AP, and the port must be placed in the VLAN that carries the AP's management and user traffic. Disabling STP or LLDP is not required and would remove useful functions.

Question 19Campus Networking Fundamentals

What does the MAC address table on a switch contain?

  1. Usernames mapped to authenticated ports
  2. VLAN IDs mapped to spanning-tree root bridges
  3. IP addresses mapped to next-hop routers
  4. MAC addresses mapped to the ports on which they were learned Correct answer.

Explanation

The MAC address table records source MAC addresses learned on each port, allowing the switch to forward frames only out the relevant port. It does not store IP routes, STP topology, or user credentials.

Question 20Campus Networking Fundamentals

A network designer wants to reduce the size of broadcast domains in a large flat Layer 2 campus network. Which approach accomplishes this?

  1. Segmenting the network into multiple VLANs with Layer 3 boundaries Correct answer.
  2. Disabling STP on all access ports
  3. Adding more switches to the same VLAN
  4. Increasing the MTU on all uplinks

Explanation

Broadcast domains are bounded by VLANs and by Layer 3 interfaces, so dividing the network into VLANs with routing between them reduces broadcast scope. Adding switches to the same VLAN enlarges the broadcast domain rather than shrinking it.

Question 21Campus Networking Fundamentals

Which two pieces of information are most useful when troubleshooting an interface that stays down after a fiber connection is made?

  1. Routing table entries and ARP cache
  2. DHCP lease time and DNS records
  3. Interface status and optical transceiver diagnostics Correct answer.
  4. VLAN database and STP timers

Explanation

Checking whether the interface is up and reading transceiver diagnostics (such as receive power) quickly isolates physical or optic issues. Routing, VLAN, and DHCP data are relevant only after the link is established.

Question 22Campus Networking Fundamentals

A campus uses MLAG between two distribution switches. What problem does MLAG primarily solve compared with a single uplink to one switch?

  1. It eliminates the need for VLANs on the access switches
  2. It replaces the need for a default gateway
  3. It provides encryption for all inter-switch traffic
  4. It removes the need to block one of the redundant uplinks in normal operation Correct answer.

Explanation

With MLAG, the two distribution switches present a single logical aggregation endpoint, so an access switch can use all its uplinks without STP blocking one. MLAG does not remove VLANs, gateways, or provide encryption.

Question 23Campus Networking Fundamentals

A host on VLAN 10 must communicate with a host on VLAN 20 through a distribution switch. What must exist on the distribution switch?

  1. A trunk port that carries both VLANs without routing
  2. A second default gateway on both hosts
  3. A Layer 3 interface in each VLAN to route between them Correct answer.
  4. A single access port in VLAN 10 only

Explanation

Inter-VLAN communication requires Layer 3 routing, so the distribution switch needs an interface (SVI or routed port) in each VLAN. A trunk alone carries the VLANs but does not route between them.

Question 24Campus Networking Fundamentals

A switch learns the same source MAC address on two different ports within a short period. What is the most likely cause?

  1. The switch has run out of MAC table entries
  2. The host is using DHCP
  3. The port is configured as a trunk
  4. A Layer 2 loop is present in the network Correct answer.

Explanation

A MAC address appearing on multiple ports is a classic symptom of a Layer 2 loop, where broadcasts and frames circulate between redundant paths. DHCP use or trunk configuration alone does not cause this symptom.

Question 25Campus Networking Fundamentals

Which design consideration best explains why a campus core is often built with Layer 3 links between core and distribution switches?

  1. It removes the need for redundant paths
  2. It eliminates the need for any routing protocol
  3. It requires fewer IP addresses than Layer 2 designs
  4. It provides fast convergence and avoids large Layer 2 failure domains Correct answer.

Explanation

Layer 3 links between core and distribution limit Layer 2 failure domains and converge quickly using routing protocols. They do not remove the need for routing protocols or redundancy.

Question 26Campus Networking Fundamentals

Which statement describes the purpose of the IEEE 802.1Q tag in an Ethernet frame?

  1. It encrypts the payload between two campus switches.
  2. It records the spanning-tree topology change counter for the frame.
  3. It carries the physical port number of the ingress interface.
  4. It identifies the VLAN membership of the frame across a shared link. Correct answer.

Explanation

802.1Q inserts a 4-byte tag whose 12-bit VLAN identifier tells receiving switches which broadcast domain the frame belongs to. The tag allows many VLANs to share one physical link between switches. It does not encrypt payloads or carry topology or port metadata.

Question 27Campus Networking Fundamentals

A campus access switch must forward traffic for VLAN 30 to a router that is one Layer 2 hop away, but no device on VLAN 30 is answering ARP for the default gateway. Which device is responsible for answering ARP for the gateway address in this design?

  1. The DHCP server that leases addresses to VLAN 30 hosts
  2. The root bridge elected by spanning tree for VLAN 30
  3. The access switch that hosts the VLAN 30 member ports
  4. The Layer 3 router or SVI that owns the gateway IP address Correct answer.

Explanation

ARP replies for an IP address come from the device that owns that address, which is the router interface or switch virtual interface configured with the gateway IP. The access switch only floods the request within the VLAN. DHCP and spanning tree play no role in answering ARP.

Question 28Campus Networking Fundamentals

Which protocol provides first-hop redundancy by letting two or more routers share a virtual MAC address and virtual IP address used by hosts?

  1. LACP
  2. LLDP
  3. VRRP Correct answer.
  4. STP

Explanation

VRRP is a first-hop redundancy protocol in which a master router answers for a shared virtual IP and virtual MAC so hosts keep a stable gateway. LLDP is neighbor discovery, LACP bundles links, and STP prevents Layer 2 loops.

Question 29Campus Networking Fundamentals

What is the primary function of a DHCP snooping binding table on a campus access switch?

  1. It records trusted client IP-to-MAC bindings used to filter untrusted DHCP and ARP traffic. Correct answer.
  2. It lists the LLDP neighbors detected on each uplink toward the distribution layer.
  3. It maps VLAN IDs to spanning-tree root priorities for each access port.
  4. It stores the MAC addresses learned from each access port for forwarding decisions.

Explanation

DHCP snooping builds a binding table of client MAC, IP, VLAN, and port from trusted DHCP exchanges, then uses it to drop spoofed DHCP server messages and, with dynamic ARP inspection, invalid ARP. The ordinary MAC table, spanning-tree priorities, and LLDP neighbor data are separate functions.

Question 30Campus Networking Fundamentals

A campus design places a Layer 3 boundary at the distribution layer, with each access switch uplinked to two distribution switches. What is the main reason to run a routing protocol between the distribution switches and the core rather than relying on static routes?

  1. It removes the requirement for a first-hop redundancy protocol at the access layer.
  2. It automatically reconverges around failed links and summarizes reachable subnets. Correct answer.
  3. It converts all access ports into routed ports automatically.
  4. It eliminates the need for any VLANs on the access switches.

Explanation

A dynamic routing protocol such as OSPF or BGP detects failures and recomputes paths without manual edits, and it supports summarization of access subnets at the distribution layer. It does not remove VLANs, replace first-hop redundancy for hosts, or change port modes.

Question 31Campus Networking Fundamentals

An engineer configures an access port with the command `switchport port-security maximum 2` and then connects a small unmanaged hub with three hosts behind it. What happens when the third host sends traffic?

  1. The port automatically converts to trunk mode to accommodate the extra hosts.
  2. The switch adds the third MAC address and ages out the oldest entry silently.
  3. The port takes the configured violation action, which by default drops offending frames and can shut the port. Correct answer.
  4. The switch forwards the traffic but logs an LLDP mismatch event.

Explanation

Port security enforces a maximum number of secure MAC addresses per port; exceeding it triggers the violation mode, and the default restrict mode drops frames from unknown sources and can generate logs or err-disable depending on configuration. The port does not change mode or silently rotate entries, and LLDP is unrelated.

Question 32Campus Networking Fundamentals

A distribution switch pair uses MLAG with a peer link. An access switch dual-homes to both peers using a single port-channel. How should the access switch port-channel be configured relative to the MLAG?

  1. As a single link to the MLAG primary with the secondary link left shut down.
  2. As a standard LACP port-channel whose member links terminate on different MLAG peers. Correct answer.
  3. As a port-channel that also includes the MLAG peer link as a member.
  4. As two separate routed links, one to each distribution peer.

Explanation

MLAG lets a downstream device form one logical port-channel with member links split across the two peers, which appear as one logical switch to LACP. The peer link is dedicated to MLAG control and data synchronization and is never a member of the downstream bundle.

Question 33Campus Networking Fundamentals

A wireless client roams between two access points on the same VLAN and briefly loses connectivity. Which Layer 2 behavior most directly explains a temporary disruption during roaming on a switched campus network?

  1. The default gateway MAC address changes to the new access point.
  2. The client's IP address must be reassigned by DHCP on the new access point.
  3. The MAC table must relearn the client MAC on the new port after the old entry ages or is updated. Correct answer.
  4. The spanning-tree topology must reconverge across the entire campus.

Explanation

When a client moves, its MAC appears on a new switch port; until the forwarding table reflects the new port, frames may be sent toward the old location. Keeping both APs in the same VLAN avoids re-addressing. Roaming does not normally trigger spanning-tree reconvergence or a gateway MAC change.

Question 34Campus Networking Fundamentals

Which statement correctly describes how a switch treats a frame arriving on an 802.1Q trunk port when the frame carries no tag?

  1. The frame is flooded to every VLAN configured on the trunk.
  2. The frame is assigned to VLAN 1 regardless of native VLAN configuration.
  3. The frame is assigned to the trunk's native VLAN. Correct answer.
  4. The frame is discarded because trunk ports accept only tagged frames.

Explanation

On an 802.1Q trunk, untagged frames are mapped to the configured native VLAN, which by default is VLAN 1 but can be changed. Tagged frames carry their own VLAN ID. Untagged frames are not automatically dropped or flooded across all VLANs.

Question 35Campus Networking Fundamentals

An engineer wants hosts in VLAN 10 on one access switch to reach hosts in VLAN 20 on a different access switch, with all inter-VLAN routing performed at the distribution layer. What is required on the link between the access switch and the distribution switch?

  1. A port-channel with LACP in active mode.
  2. A routed port with an IP address in VLAN 10.
  3. A trunk that carries both VLAN 10 and VLAN 20. Correct answer.
  4. An access port assigned to VLAN 10 only.

Explanation

Because both VLANs must reach the distribution layer for routing, the uplink must carry both VLANs, which requires a trunk. An access port in a single VLAN or a routed port would not deliver the second VLAN's traffic to the router. A port-channel is optional and does not by itself carry multiple VLANs.

Question 36Campus Networking Fundamentals

A campus core uses Layer 3 links to each distribution block. Which outcome does this design most directly provide compared with a Layer 2 core?

  1. Automatic assignment of IP addresses to all access-layer hosts.
  2. Fast convergence and loop prevention through routing rather than large spanning-tree domains. Correct answer.
  3. Elimination of the need for any routing protocol in the campus.
  4. A single broadcast domain spanning every distribution block.

Explanation

A routed core segments the campus into smaller Layer 2 domains and relies on routing convergence and equal-cost paths instead of spanning tree to prevent loops. It does not merge broadcast domains, remove the need for routing protocols, or provide host addressing.

Question 37Campus Networking Fundamentals

A switch reports that an access port is in an err-disabled state after a user connects a device. Which recovery mechanism allows the port to return to service automatically after a configured interval without manual intervention?

  1. Increasing the port's spanning-tree cost value.
  2. Configuring errdisable recovery for the specific cause with a recovery timer. Correct answer.
  3. Setting the port to trunk mode with a native VLAN.
  4. Enabling LLDP transmit and receive on the interface.

Explanation

EOS can automatically re-enable err-disabled ports when errdisable recovery is enabled for the triggering cause and a recovery interval is set. LLDP, trunk settings, and spanning-tree cost do not clear an err-disabled condition.

Question 38Campus Networking Fundamentals

Two hosts on the same VLAN report intermittent connectivity. The switch logs show MAC flapping between two access ports. Which condition is the most likely root cause?

  1. The default gateway is misconfigured on the hosts.
  2. The DHCP lease time is too short for the subnet.
  3. The trunk native VLAN is set to VLAN 1.
  4. A Layer 2 loop exists between the two ports. Correct answer.

Explanation

MAC flapping occurs when the same source MAC is learned alternately on two ports, which is typical of a Layer 2 loop or a duplicated device. Gateway misconfiguration, DHCP lease length, and native VLAN defaults do not cause repeated relearning of one MAC on two ports.

Question 39Campus Networking Fundamentals

A campus uses OSPF between distribution and core. An engineer adds a new distribution block and wants its access subnets summarized into the core. Where should the summary be configured and why?

  1. On each access switch, because summaries are generated by the device that owns the subnets.
  2. On the DHCP server, because summaries follow address lease ranges.
  3. On the core router, because summaries must be injected at the area 0 backbone.
  4. On the distribution router at the area boundary, because summarization is performed by the ABR for inter-area routes. Correct answer.

Explanation

In OSPF, area border routers generate summarized inter-area LSAs for networks behind them, so the summary belongs on the distribution router that borders the backbone. Access switches are typically Layer 2 and do not originate OSPF summaries, and the core receives rather than creates the summary.

Question 40Campus Networking Fundamentals

An access switch dual-homed to an MLAG pair receives a broadcast frame from a host. How does the MLAG pair prevent duplicate copies of that broadcast from reaching the peer link and looping?

  1. The peer link and downstream bundle members are kept in a forwarding state, but MLAG filtering ensures only one peer forwards flooded traffic toward the pair. Correct answer.
  2. Broadcast frames are dropped at the access switch before reaching the MLAG pair.
  3. Only the MLAG secondary forwards all flooded traffic to the core.
  4. The peer link is placed in a spanning-tree blocking state for all VLANs.

Explanation

MLAG keeps both peers active and uses internal filtering rules so that flooded traffic arriving from a downstream bundle is not re-forwarded across the peer link to the other peer's downstream path. The peer link remains forwarding for control and failover traffic. Blocking it or dropping broadcasts would break the design.

Question 41Arista Extensible Operating System (EOS)

Which statement best describes the architecture of Arista EOS?

  1. It runs a single monolithic kernel image that bundles all routing and management processes.
  2. It relies on a proprietary real-time OS with no Linux component.
  3. It runs all control-plane processes inside the kernel to reduce context switching.
  4. It uses a Linux kernel with routing and management processes running in separate protected user-space address spaces. Correct answer.

Explanation

EOS is built on an unmodified Linux kernel, with switching, routing, and management agents running as separate user-space processes. This process isolation lets individual agents restart without rebooting the whole switch. It also enables features like stateful restart and in-service upgrades.

Question 42Arista Extensible Operating System (EOS)

An engineer wants to see the current running configuration on an Arista switch. Which command displays it?

  1. show version
  2. show boot-config
  3. show running-config Correct answer.
  4. show startup-config

Explanation

The `show running-config` command displays the active configuration currently in effect. `show startup-config` shows what will be loaded at the next boot. The running configuration is what EOS uses in real time.

Question 43Arista Extensible Operating System (EOS)

Which CLI mode allows an administrator to make configuration changes on an Arista switch?

  1. Privileged EXEC mode
  2. Interface range mode
  3. User EXEC mode
  4. Global configuration mode Correct answer.

Explanation

Configuration changes are made from global configuration mode, entered with the `configure terminal` command. Interface and other sub-modes are reached from within global configuration mode. EXEC modes are for viewing and monitoring.

Question 44Arista Extensible Operating System (EOS)

What is the primary purpose of the Arista EOS stateful restart feature?

  1. To upgrade the EOS image without a reboot.
  2. To synchronize configuration between stack members.
  3. To reload the switch configuration from flash automatically.
  4. To restart a failed agent while preserving its forwarding and protocol state. Correct answer.

Explanation

Stateful restart allows a failed protocol or control agent to restart while retaining its prior state, avoiding disruption to the data plane. This leverages the process isolation of EOS. It is not the same as a full image upgrade or config reload.

Question 45Arista Extensible Operating System (EOS)

Which command saves the running configuration so it persists after a reload?

  1. show running-config
  2. write erase
  3. copy running-config startup-config Correct answer.
  4. reload now

Explanation

`copy running-config startup-config` persists the active configuration to the startup configuration. Without this, changes made in the running configuration are lost on reload. `write erase` clears configuration rather than saving it.

Question 46Arista Extensible Operating System (EOS)

An engineer needs to view the EOS software version and boot image details. Which command is most appropriate?

  1. show inventory
  2. show interfaces status
  3. show logging
  4. show version Correct answer.

Explanation

`show version` reports the EOS software release, boot image, hardware model, and uptime. It is the standard command for confirming software version. Other show commands target interfaces, hardware inventory, or logs.

Question 47Arista Extensible Operating System (EOS)

What does the EOS Sysdb (system database) primarily provide?

  1. A remote logging repository for syslog messages.
  2. A persistent on-disk store of configuration files.
  3. A central in-memory data model that agents read and write to share state. Correct answer.
  4. A database for storing user credentials only.

Explanation

Sysdb is an in-memory system database that acts as a central data model through which EOS agents publish and consume state. It enables loose coupling between processes. It is not a disk-based config store or a logging repository.

Question 48Arista Extensible Operating System (EOS)

Which mechanism allows EOS to apply configuration changes with minimal disruption by validating and committing them atomically?

  1. Startup-config reload
  2. Flash partitioning
  3. Boot-config editing
  4. Configuration sessions Correct answer.

Explanation

Configuration sessions let an engineer stage changes, review a diff, and commit them atomically, reducing the risk of partial or disruptive edits. This is a core EOS workflow for safe change management. Other options relate to boot or storage, not atomic config commit.

Question 49Arista Extensible Operating System (EOS)

In EOS, which command creates a named configuration session?

  1. configure session <name> Correct answer.
  2. session start <name>
  3. config terminal name <name>
  4. commit session <name>

Explanation

The `configure session <name>` command enters a named configuration session where changes can be staged. Within the session, `show session-config diffs` and `commit` are used to review and apply. The other commands are not valid EOS syntax for creating a session.

Question 50Arista Extensible Operating System (EOS)

Which command within a configuration session shows the pending differences from the running configuration?

  1. show config pending
  2. show session-config diffs Correct answer.
  3. show running-config diff
  4. show session-config named <name>

Explanation

`show session-config diffs` displays the differences between the staged session and the running configuration. This lets engineers review changes before committing. Other listed commands are not valid EOS syntax for this purpose.