Arista ~ ACE Level One Exam

The financial/cost calculations on a network utilizing LACP, which gave faster failover and increased capacity but wasn't being used to the fullest extent, drove the industry to adopt MLAG as the next protocol. MLAG (Multi-Chassis Link Aggregation) allows for the creation of a logical link aggregation group between two switches, providing redundancy and load balancing capabilities. By implementing MLAG, organizations can fully utilize the benefits of link aggregation while ensuring high availability and improved network performance.

The term used to describe the fundamental part of routing where routers are connected together to exchange the networks they "know" about is called "Neighbors".

Within an Autonomous System (AS), routers are configured to "speak" the same language/protocol. The protocol used within an AS is known as an Interior Gateway Protocol (IGP). IGPs are used to exchange routing information between routers within the same AS. This allows for efficient and effective communication and routing within the network.

The other problem that was solved with LACP is increased capacity. LACP (Link Aggregation Control Protocol) allows for the bundling of multiple physical network links into a single logical link, increasing the overall bandwidth and capacity of the network connection. By combining multiple links, LACP provides a higher capacity for data transmission, enabling faster and more efficient network communication.

With MLAG (Multi-Chassis Link Aggregation) configured, STP (Spanning Tree Protocol) sees multiple switches as one. MLAG allows multiple switches to act as a single logical switch, providing redundancy and load balancing. By presenting themselves as a single switch to STP, MLAG eliminates the need for STP to block redundant links, resulting in improved network efficiency and faster convergence.

The Arista software known as EOS is also named Cloud Vision because it provides a comprehensive and integrated approach to cloud networking. This software enables organizations to build and manage cloud networks efficiently and securely. It offers advanced features and capabilities for network automation, virtualization, and scalability, making it an ideal solution for cloud computing environments. By integrating cloud vision into their software, Arista ensures that their customers have a clear and holistic view of their cloud networks, allowing them to optimize performance and streamline operations.

The statement is true. DARPA (Defense Advanced Research Projects Agency) was indeed involved in the development of Ethernet. In the 1970s, DARPA funded the research and development of the ARPANET, which was a precursor to the modern internet. Ethernet, a widely used networking technology, was developed as part of the ARPANET project. Therefore, DARPA can be credited as being instrumental in the early stages of Ethernet's development.

In the late 80's, the product that eliminated network collisions altogether was a switch. Unlike a hub, which broadcasts data to all connected devices, a switch intelligently directs data only to the intended recipient. This prevents collisions and allows for simultaneous communication between multiple devices on a network. A router, on the other hand, is responsible for connecting multiple networks and directing traffic between them. Bridging refers to the process of connecting two separate networks to create a larger network.

The command switchport mode trunk configures the interface to operate as a trunk port, which can carry traffic from multiple VLANs, enabling communication between VLANs across switches.

Flow based load balancing is used with ECMP (Equal Cost Multipath) in modern networking. Unlike the old days where individual packets were load balanced, flow based load balancing distributes traffic based on flows, which are a sequence of packets with the same source and destination IP addresses, protocol, and port numbers. This approach ensures that packets belonging to the same flow are sent to the same destination, improving performance and reducing the chances of out-of-order packet delivery.

Layer 2 in the OSI model is known as Switching. This layer is responsible for the efficient and reliable transfer of data between devices on a local area network (LAN). Switches operate at the data link layer and use MAC addresses to forward data packets to the correct destination. They make forwarding decisions based on the MAC address in the frame's header, allowing for efficient communication within a LAN. Switching helps to improve network performance by reducing collisions and optimizing the flow of data.

The concept of avoiding a single point of failure is fundamental in networking. This means that the network is designed in such a way that if one component or link fails, it does not cause a complete network outage. By having redundant components and multiple paths, the network can continue functioning even if one part fails. This ensures reliability and minimizes the risk of downtime.

In the mid 80's, the networking device that brought devices together to access group resources, like servers and printers, was a hub. A hub is a simple networking device that connects multiple devices in a network, allowing them to communicate with each other. It operates at the physical layer of the network and broadcasts all incoming data to all connected devices. However, hubs have limitations in terms of bandwidth and security, which led to the development of more advanced networking devices like switches.

Segmentation refers to the industry term for the ability to separate functions like data, VoIP, Wi-Fi, storage, etc. in the network. This means that different types of traffic can be isolated and managed independently, allowing for more efficient and secure network operations. Segmentation helps in optimizing network performance and improving overall network security by preventing unauthorized access and minimizing the impact of any potential breaches.

A port channel is a communication link between two switches that is supported by matching channel group interfaces on each switch. It is also referred to as a LAG, which stands for Link Aggregation Group. LAG allows multiple physical links to be bundled together to increase bandwidth and provide redundancy. This helps in improving network performance and ensuring high availability.

Fiber optics provides improvement over cabling by eliminating crosstalk. Crosstalk is the interference caused by signals from adjacent cables interfering with each other. By using fiber optics, which transmit data using light signals instead of electrical signals, this interference is eliminated. This results in a clearer and more reliable signal transmission.

PortFast is a feature in Cisco switches that allows a port to bypass the Spanning Tree Protocol (STP) listening and learning states and transition directly from blocking to forwarding state. This means that when PortFast is enabled on a port, it overrides STP and allows the port to immediately start forwarding traffic. In the given answer, it is stated that PortFast overrides STP and the Edge Port changes from blocking to forwarding, which accurately describes the functionality of PortFast.

An IP address can be assigned to a VLAN, creating a switched virtual interface (SVI) that can be reached regardless of the status of the physical interface. The physical interface can be in an up or down state, meaning it can be operational or not operational, but the SVI will still be reachable through the assigned IP address. This allows for connectivity and communication to the VLAN even if the physical interface is not currently active or functioning properly.

Laptops changed the networking landscape for companies by providing roaming computing power. With the advent of laptops, employees were no longer tied to their desks and could work from anywhere, enabling greater flexibility and productivity. Laptops allowed for easy access to company networks and resources while on the go, revolutionizing the way businesses operated and communicated.

VPNs are not typically included in a NetOps tool suite. NetOps tool suites consist of various tools and technologies used for network operations, management, and monitoring. These tools include network controllers, which are used to manage and control network devices, APIs (Application Programming Interfaces) for integration and automation, and programming languages like Python for scripting and automation purposes. However, VPNs are not typically considered as part of a NetOps tool suite, as they are a separate technology used for secure remote access to a network.

VRRP (Virtual Router Redundancy Protocol) was developed to solve the router "black hole" syndrome where data packets still went to a router that was "dead" or "off-line". VRRP allows for multiple routers to work together in a group, with one acting as the master and the others as backups. If the master router fails, one of the backups takes over as the new master, ensuring that data packets are still routed correctly even if one of the routers is offline.

Adding "priority" commands at the VLAN level allows switches to become the root switch in a spanning tree protocol (STP) network. The root switch is the central switch that all other switches in the network are connected to. By configuring the priority of a switch to a lower value, it becomes more likely to be elected as the root switch. This can be useful in controlling the network topology and ensuring that a specific switch becomes the root switch, which can help in optimizing network performance and reducing the chances of network loops.

In MLAG configurations, each switch must have identical domain IDs. This is because the domain ID is used to uniquely identify each switch in the MLAG domain. Having identical domain IDs ensures that the switches can properly communicate and synchronize with each other, allowing for seamless failover and load balancing between the switches. If the switches had different domain IDs, they would not be recognized as part of the same MLAG domain and would not be able to function together effectively.

All the statuses listed are accurate and can be associated with Multi-chassis Link Aggregation Group (MLAG) configuration. Here’s what each status generally means:

Failed: This status indicates that the MLAG configuration or connection has encountered an error.

Connected: This status shows that the MLAG peers are successfully connected.

Domain Mismatch: This status is displayed when there is a mismatch in the domain configuration between the MLAG peers.

Invalid Peer: This status is shown when the MLAG peer is not valid or not correctly configured.

So, none of the statuses listed are inaccurate. 

The correct answer is the 80's. The OSI (Open Systems Interconnect) model was created in the 1980s. This model is a conceptual framework that standardizes the functions of a communication system into seven different layers. It was developed by the International Organization for Standardization (ISO) to facilitate interoperability between different computer systems and networks.

Cloud computing provides several benefits, including metered service, API driven functionality, and multi-tenancy. However, it does not provide engineer servicing. This means that cloud computing does not require the direct involvement or assistance of engineers for maintenance or troubleshooting purposes. Instead, the responsibility for servicing and maintaining the cloud infrastructure lies with the cloud service provider.

IS-IS (Intermediate System to Intermediate System) is the routing protocol that uses the 128-bit address space. In contrast, OSPF (Open Shortest Path First) uses a 32-bit address space. The 128-bit address space in IS-IS allows for a larger number of addressable entities and supports the scalability requirements of modern networks.

In ZTP (Zero Touch Provisioning) mode, if no startup-config is found, the switch looks for DHCP next. This means that the switch will attempt to obtain its configuration information from a DHCP server. DHCP is a network protocol that automatically assigns IP addresses and other network configuration parameters to devices on a network. By looking for DHCP, the switch can receive its configuration information without the need for manual intervention, allowing for easier and more automated provisioning of network devices.

Zero Touch Provisioning (ZTP) uses Option 66 (TFTP server IP) and Option 67 (file name) from DHCP to automatically configure devices. An FTP server is not typically required for ZTP, as TFTP is the standard protocol used for file transfer in this process.

The given statement is true. The ZTP (Zero Touch Provisioning) Server was indeed created by Arista employees.

Novell no longer has networking software that runs over ethernet. This means that Novell has either discontinued or phased out their networking software that was compatible with ethernet connections.

ARP is a Layer 2 protocol used to map IP addresses (Layer 3) to MAC addresses (Layer 2). It relies on Ethernet and MAC addresses but does not use gateways directly in its process. Gateways operate at Layer 3 to route traffic between networks.

Corporations' biggest concern with leased WAN connectivity is protection. Since WAN connectivity is a public and shared infrastructure, corporations need to ensure the security and confidentiality of their data and communications. They must protect their network from unauthorized access, data breaches, and other cyber threats. This includes implementing robust security measures such as firewalls, encryption, and intrusion detection systems to safeguard their sensitive information and maintain the integrity of their network.

The Back Bone Router (BB) connects routers within the same Area 0. Area 0 is the backbone area in a network running OSPF (Open Shortest Path First) protocol. The backbone area is responsible for connecting all other areas in the network. The Back Bone Router acts as a gateway for routers within Area 0, allowing them to communicate with routers in other areas.

The mapping in LACP takes place instantly. This means that when a flow needs to shift to a new 'bucket' or port, it happens immediately without any noticeable delay. Unlike STP, which takes some time to converge and reconfigure the network, LACP provides a faster and seamless transition for the flows.

Binary is the correct format for identifying IP addresses. IP addresses are made up of a series of numbers, and in binary format, these numbers are represented using only two digits, 0 and 1. Each section of the IP address is divided into 8 bits, resulting in a total of 32 bits for the entire address. This binary representation allows for efficient data transmission and routing on computer networks.

The Arista EOS architecture offers several benefits, including fault isolation, 3rd party integration, and fault repair. However, the installation of RPMs with little downtime is not listed as a benefit of Arista EOS.

The ROOT device in STP (Spanning Tree Protocol) continues to send BPDUs (Bridge Protocol Data Units) every 2 seconds to maintain the STP topology and react to failures. BPDUs are used by STP to exchange information between network switches and determine the root bridge, as well as to prevent loops in the network. By sending BPDUs regularly, the ROOT device ensures that the network remains stable and can quickly respond to any failures or changes in the network topology.

In Loopback Interface Configuration, the loopback numbers range from 0 to 1000. This means that the loopback interface can be assigned a number between 0 and 1000.

Network engineers need to understand MAC addresses (hardware identifiers), the binary system (fundamental to IP addressing and subnetting), IP subnetting (for dividing networks), and dotted decimal notation (human-readable IP address format) at all stages of network design and management.

In STP (Spanning Tree Protocol) mode, the total transition time typically takes 50 seconds. This means that it takes 50 seconds for the network to go through the process of selecting the root bridge, determining the best path, and establishing connectivity. During this time, the network undergoes a series of calculations and adjustments to prevent loops and ensure a stable network topology.

Arista switches support four types of interfaces: Port-channel, Management, and Ethernet. However, Loopback is not a supported type of interface.

A sanity check is a term used to identify configuration inconsistencies in MLAG configurations. It refers to a process of verifying that the configuration settings are logical and consistent, ensuring that there are no obvious errors or conflicts. By performing a sanity check, any potential issues or misconfigurations can be detected early on, allowing for prompt resolution and preventing further complications.

ECMP (Equal Cost Multipath) is a routing technique that allows for load balancing across multiple paths with equal costs. In this context, "the chips" refer to the hardware chips used in networking devices such as routers and switches. ECMP relies on the capabilities and functionality of these chips to distribute traffic across multiple paths effectively. Therefore, the correct answer is "The chips."

The initial state of a switch is "Root". This is because when a switch is first powered on or reset, it starts in a default state known as the root state. In this state, the switch does not have any configuration or VLAN settings applied. It is essentially a blank slate waiting to be configured by an administrator.

PoE (Power over Ethernet) allows electrical power to be transmitted along with data over standard Ethernet cables. This innovation eliminated the need for separate power cables for devices like IP phones, cameras, and wireless access points, simplifying installation and reducing costs.

The term “Notification” is used to describe the operational status of a router in a network. This term refers to the messages that a router sends to indicate its status, such as whether it’s up (operational) or down (not operational). These notifications can help network administrators monitor the health and performance of the network. 

It is possible to send data or requests to a host that no longer exists on the network. This can happen if the host was temporarily disconnected or turned off, but it may still exist on the network. Additionally, it is also possible to send data or requests to a host that has been permanently removed from the network, but the sender may not receive a response.

The networking vendors implemented variations of the standards and mixed them with their own solutions to solve the problem without interrupting their customers' current designs. This approach locked the customers into their solution, ensuring that their revenues would be protected. By not fully implementing the standard and providing a solution that seamlessly integrated with their customers' existing infrastructure, the vendors were able to retain their customer base and continue generating revenue.

Arista recommends BGP for most leaf-spine data center designs. BGP, or Border Gateway Protocol, is a routing protocol that is commonly used in large-scale networks, such as data centers. It provides scalability and flexibility in routing decisions, making it suitable for the complex and dynamic nature of leaf-spine architectures. BGP allows for efficient traffic distribution and load balancing across the network, ensuring optimal performance and reliability. Additionally, BGP supports advanced features like route filtering and policy-based routing, which are essential in data center environments.

The IMP (Internet Message Protocol) is not part of an IP (Internet Protocol) header. The IP header contains various fields such as the checksum, destination address, and IHL (Internet Header Length), which specifies the length of the IP header in 32-bit words. However, the IMP is not a standard field in the IP header and is not used in the routing or delivery of IP packets.

When many operating systems are required to manage a network, we call this a "Silo'd" operating system. In a silo'd operating system, each operating system functions independently and is responsible for managing a specific part of the network. This can result in a lack of interoperability and coordination between different operating systems, making it difficult to manage the network as a whole.

The correct answer is usually between 10 and 100. When an HTTP request is made, it often passes through multiple computers or servers before reaching its destination. Each of these intermediate points can be considered as a transaction in the sniffer trace. Therefore, it is common for there to be between 10 and 100 transactions recorded in the sniffer trace before the request is completed.

The networking of the past, which is referred to as "Legacy," is now commonly known as "Virtual" in today's context. This term signifies the shift towards virtualized networking technologies and the use of virtual machines, software-defined networks, and network virtualization to create flexible and scalable network infrastructures.

A Virtual Private Network (VPN) provides encapsulation of the original packet into the data portion of another packet. This means that the original packet is wrapped inside another packet, which helps to secure the data being transmitted over the network. This encapsulation process adds an extra layer of protection by encrypting the original packet, making it difficult for unauthorized individuals to intercept and access the data. By encapsulating the packet, VPNs ensure the privacy and confidentiality of the information being transmitted, making it an essential tool for secure communication over public networks.

The port priority of LACP determines the port that is active in a LAG in fallback mode. In this mode, if the active port fails or goes offline, the LACP protocol will automatically switch to a backup port with a lower priority. This ensures that there is always an active port in the LAG, providing redundancy and preventing network downtime.

The given statement mentions that "Applications perform with high-bandwidth and high-latency" is not a feature of the Leaf-Spine Architecture. This means that in the Leaf-Spine Architecture, applications do not typically operate with both high-bandwidth and high-latency.

Scripts are run from the switch. The switch is a networking device that connects multiple devices within a network. It is responsible for forwarding data packets between devices and ensuring efficient communication. Scripts can be executed on the switch to automate certain tasks or configure network settings.

VARP stands for Virtual ARP (Address Resolution Protocol) and it was developed by Arista to solve the router "black hole" syndrome. This syndrome occurs when data packets are still sent to a router that is "dead" or "off-line". VARP allows for the creation of a virtual MAC address that can be associated with a group of routers. When a router in the group becomes unavailable, VARP automatically reassigns the virtual MAC address to another router in the group, ensuring that the packets are properly routed even if one router is offline.

Culture is the third source of Arista's quality. While architecture and testing play a significant role in ensuring quality, culture also plays a crucial part. A positive and collaborative culture within the organization promotes teamwork, innovation, and a commitment to delivering high-quality products. It influences the mindset and behaviors of employees, encouraging them to prioritize quality in their work. By fostering a culture that values quality, Arista can consistently deliver products that meet or exceed customer expectations.

After the synchronization process is complete, interfaces exchange one LACP PDU (Link Aggregation Control Protocol Protocol Data Unit) every 30 seconds. This periodic exchange helps to maintain the link aggregation and ensure the proper functioning of the bonded interfaces. By exchanging PDUs at regular intervals, the interfaces can stay updated about the status and availability of each other, allowing for efficient load balancing and fault tolerance in link aggregation.

VRF (Virtual Routing and Forwarding) allows multiple instances of routing tables to coexist on the same router, effectively segmenting network traffic. This separation enhances data security by isolating traffic between different virtual networks. While VRF can improve network management, it does not inherently release packets faster or auto-configure on routers without setup.