[2023年10月]更新のEricsson ECP-206試験練習テスト問題
更新された認定試験ECP-206問題集で練習テスト問題
質問 # 28
In OSPFv2, which route characteristic is used to determine the best path?
- A. delay
- B. packet loss
- C. cost
- D. jitter
正解：C
解説：
Explanation
In OSPFv2, the route characteristic that is used to determine the best path is the cost. The cost is a metric that represents the link bandwidth, delay, reliability, or other factors. The cost is inversely proportional to the bandwidth, meaning that a higher bandwidth link has a lower cost. The cost of a route is calculated by adding the costs of all links along the path. OSPFv2 uses the following formula to calculate the cost of an interface:
Cost = Reference bandwidth / Interface bandwidth in bps
The reference bandwidth is a constant value that can be configured by the network administrator. By default, it is 100 Mbps. The interface bandwidth is the actual bandwidth of the interface in bits per second. For example, if an interface has a bandwidth of 10 Mbps, its cost would be 100 Mbps / 10 Mbps = 101415.
OSPFv2 does not use jitter, packet loss, or delay as route characteristics to determine the best path. Jitter is the variation in latency or delay between packets. Packet loss is the percentage of packets that are dropped or corrupted during transmission. Delay is the time it takes for a packet to travel from source to destination. These characteristics are not part of the OSPFv2 protocol and are not advertised in OSPFv2 LSAs1617.
References: OSPF Metric cost Calculation Formula Explained - ComputerNetworkingNotes, OSPF Cost - OSPF Routing Protocol Metric Explained - Study-CCNA, Open Shortest Path First - Wikipedia, OSPF Metric
= Cost - Cisco
質問 # 29
What is the correct ordering (outer to inner) of packet headers in an IP/MPLS packet?
- A. MPLS, IP, Ethernet
- B. Ethernet, MPLS, IP
- C. Ethernet, IP, MPLS
- D. IP, MPLS, Ethernet
正解：B
解説：
Explanation
The correct ordering (outer to inner) of packet headers in an IP/MPLS packet is Ethernet, MPLS, IP. An IP/MPLS packet is a packet that is encapsulated with an MPLS label stack between the Ethernet header and the IP header. The Ethernet header contains the source and destination MAC addresses and the EtherType field that indicates the type of the payload. The MPLS label stack contains one or more labels that are used for forwarding decisions by the MPLS routers. Each label consists of four fields: label value, experimental bits, bottom of stack, and time to live. The IP header contains the source and destination IP addresses and other information for routing and fragmentation. The order of the headers is important because it determines how the packet is processed by different devices in the network12.
References: MPLS Label Stack - Cisco, MPLS Fundamentals: 3 - MPLS Packet Forwarding
質問 # 30
What is the subnet address for 10.57.126.156/29?
- A. 10.57.126.156
- B. 10.57.126.144
- C. 10.57.126.152
- D. 10.57.126.0
正解：C
解説：
Explanation
The subnet address for 10.57.126.156/29 is 10.57.126.152. To find the subnet address, we need to perform a bitwise AND operation between the IP address and the subnet mask. The subnet mask for /29 is
255.255.255.248, which in binary is 11111111.11111111.11111111.11111000. The IP address in binary is
00001010.00111001.01111110.10011100. The result of the AND operation is
00001010.00111001.01111110.10011000, which in decimal is10.57.126.152. References: Ericsson IP Networking - IP Addressing, Software Installation and Upgrade Overview (Junos OS)
質問 # 31
What is used for Ethernet loop avoidance?
- A. Split-Horizon
- B. Spanning-Tree
- C. Poison-Reverse
- D. Time-to-Live (TTL)
正解：B
解説：
Explanation
Spanning-Tree is used for Ethernet loop avoidance. Spanning-Tree is a protocol that prevents loops in Ethernet networks by creating a logical tree topology of the network switches. Spanning-Tree blocks some of the redundant links between switches to ensure that there is only one active path between any two nodes in thenetwork. Spanning-Tree also detects and recovers from link failures by activating alternative paths when needed56.
References: Network loops and loop avoidance - Medium, Spanning Tree Protocol - Wikipedia
質問 # 32
What is a reason for using VLANs in an IP network?
- A. to isolate hosts within the same IP subnet
- B. to implement virtual routing
- C. to enable MAC address learning on a router port
- D. to isolate hosts across multiple IP subnets
正解：A
解説：
Explanation
A reason for using VLANs in an IP network is to isolate hosts within the same IP subnet. VLANs (Virtual LANs) are logical grouping of devices in the same broadcast domain. VLANs are usually configured on switches by placing some interfaces into one broadcast domain and some interfaces into another. Each VLAN acts as a subgroup of the switch ports in an Ethernet LAN. VLANs allow network administrators to group hosts together even if the hosts are not directly connected to the same network switch. By using VLANs, hosts within the same IP subnet can be separated into different broadcast domains, which enhances security, reduces network congestion, and simplifies network management78.
References: 8 Different Types of VLANs in TCP/IP Networks, What is a VLAN? - Study-CCNA
質問 # 33
Which two statements are true about router node hardening? (Choose two.)
- A. IPsec should be implemented to secure IGP routing protocols.
- B. Any unnecessary services should be disabled within each context.
- C. Enabling syslog ensures system events are logged to a remote server.
- D. LDAP, using the TLS protocol, should be implemented for remote logging.
正解：B、C
解説：
Explanation
Two statements that are true about router node hardening are:
Any unnecessary services should be disabled within each context. Router node hardening is a process of securing a router from unauthorized access and attacks by applying various configurations and policies.
One of these configurations is to disable any services that are not needed for the router's functionality or purpose, such as telnet, ftp, http, etc. This reduces the attack surface of the router and prevents potential exploits of these services91.
Enabling syslog ensures system events are logged to a remote server. Syslog is a protocol that allows a router to send system messages and events to a remote server for logging and analysis. By enabling syslog on a router, network administrators can monitor the router's activity and performance, troubleshoot problems, detect anomalies, and audit security events101.
References: Cisco Router Hardening Step-by-Step | SANS Institute, Security Hardening Checklist Guide for Cisco Routers/Switches in 10 Steps, CCNA SEC: Router Hardening - Cisco Press
質問 # 34
Which statement accurately defines an Autonomous System (AS)?
- A. An AS is a group of networks directly connected to each other that can distribute eBGP information using directly established links.
- B. An AS is a set of routers under a single administration, using an interior gateway protocol and common metrics to route packets within the AS.
- C. An AS is a collection of IS-IS routes imported into BGP and presented in such a way that networks connected to the AS have a global overview of the network.
- D. An AS is a network that is capable of autonomously forwarding packets, regardless of direct or indirect connectivity to the Internet.
正解：B
解説：
Explanation
The statement that accurately defines an Autonomous System (AS) is that an AS is a set of routers under a single administration, using an interior gateway protocol and common metrics to route packets within the AS.
An AS is a logical grouping of networks that share a common routing policy and operate under a single administrative authority. An AS can be a single network or a collection of networks that are interconnected by routers. An AS uses an interior gateway protocol (IGP), such as OSPF or IS-IS, to exchange routing information within the AS. An IGP uses common metrics, such as hop count or bandwidth, to determine the best path to each destination within the AS. An AS also has a unique number assigned by IANA, called an AS number (ASN), which identifies the AS in interdomain routing .
References: [Autonomous system (Internet) - Wikipedia], [What Is an Autonomous System? - Cisco]
質問 # 35
Which two features does IPsec provide? (Choose two.)
- A. protecting the length of packets from discovery
- B. protecting packets from modification
- C. controlling the path through the network
- D. hiding the content of packets from observation
正解：B、D
解説：
Explanation
IPsec provides two main features: protecting packets from modification and hiding the content of packets from observation. IPsec protects packets from modification by using cryptographic algorithms to generate and verify message authentication codes (MACs) or digital signatures for each packet. These mechanisms ensure that the packets have not been tampered with or altered in transit by unauthorized parties. IPsec hides the content of packets from observation by using encryption algorithms to scramble the payload of each packet. This prevents eavesdroppers or interceptors from reading or analyzing the data carried by the packets12.
References: What is IPsec? | How IPsec VPNs work | Cloudflare, IPsec - Wikipedia
質問 # 36
How many different priorities are available to use in a VLAN header?
- A. 0
- B. 1
- C. 2
- D. 3
正解：B
解説：
Explanation
There are 8 different priorities available to use in a VLAN header. A VLAN header is a 4-byte field that is inserted into an Ethernet frame to indicate the VLAN membership and priority of the frame. The VLAN header consists of two subfields: the tag protocol identifier (TPID) and the tag control information (TCI). The TCI subfield contains three subfields: the priority code point (PCP), the drop eligible indicator (DEI), and the VLAN identifier (VID). The PCP subfield is a 3-bit field that specifies the priority level of the frame, ranging from 0 (lowest) to 7 (highest). The PCP values can be used to implement quality of service (QoS) mechanisms on bridges and switches12.
References: HTML rt Tag - W3Schools, VLAN 0 Priority Tagging Support - Cisco
質問 # 37
In an Ericsson Router 6000, which command is used to begin making changes to the router settings?
- A. capabilities
- B. set metric
- C. commit
- D. configure
正解：D
解説：
Explanation
The command that is used to begin making changes to the router settings in an Ericsson Router 6000 is configure. This command enters the configuration mode, where various commands can be used to modify the router parameters, such as interfaces, protocols, services, security, etc. To exit the configuration mode, the command end can be used. To save the changes made in the configuration mode, the command commit can be used56.
References: Router 6000 Series - Ericsson, Ericsson Router 6000 series (6471/6672/6675) Commands for
2G/3G/4G/5G technologies... - YouTube
質問 # 38
Which two statements are correct for LDP? (Choose two.)
- A. LSRs send UDP hello messages for neighbor discovery.
- B. LSRs use TCP to negotiate LDP session parameters.
- C. LSRs send ICMP hello messages for neighbor discovery
- D. LSRs use UDP for session establishment.
正解：A、B
解説：
Explanation
Two statements that are correct for LDP are:
LSRs send UDP hello messages for neighbor discovery. LDP is a protocol that distributes labels for MPLS forwarding along the shortest path calculated by an IGP. LDP uses two types of messages:
discovery messages and session messages. Discovery messages are used to discover and maintain adjacency with other LSRs that support LDP. Discovery messages are sent as UDP datagrams to the well-known multicast address 224.0.0.2 (all routers on this subnet) on port 64634.
LSRs use TCP to negotiate LDP session parameters. Session messages are used to establish, maintain, and terminate LDP sessions between LSRs. Session messages are also used to exchange label mappings, notification messages, and keepalive messages. Session messages are sent as TCP segments to port
64634.
References: Ldp | Microsoft Learn, Label Distribution Protocol - Wikipedia
質問 # 39
Which conceptual table created by routing protocols is used when processing an IP packet?
- A. forwarding information base
- B. label information base
- C. traffic engineering data base
- D. management information base
正解：A
解説：
Explanation
The conceptual table created by routing protocols that is used when processing an IP packet is the forwarding information base (FIB). The FIB is a table that contains the bestroutes to reach each destination network prefix, along with the outgoing interface and the next-hop address for each route. The FIB is derived from the routing information base (RIB), which is a table that contains all the routes learned from different routing protocols and sources. The FIB is used by the router to make fast forwarding decisions for each incoming packet, based on its destination address12.
References: Security Hardening Checklist Guide for Cisco Routers/Switches in 10 Steps, VLAN - Wikipedia
質問 # 40
In your network, video traffic is being marked with DSCP code AF31.
Based on industry standard practice, which code would you use to assign higher priority to VoIP traffic?
- A. AF21
- B. AF11
- C. DF
- D. EF
正解：D
解説：
Explanation
The code that is commonly used to assign higher priority to VoIP traffic is EF, which stands for Expedited Forwarding. EF is a per-hop behavior (PHB) defined by the Differentiated Services (DiffServ) model for QoS.
EF provides low delay, low jitter, and low loss for real-time applications such as VoIP. EF is marked by setting the DSCP value to 101110, which corresponds to decimal 4678. AF31, which stands for Assured Forwarding class 3 low drop probability, is another PHB defined by DiffServ, but it provides lower priority than EF. AF31 is marked by setting the DSCP value to 011010, which corresponds to decimal 2678. DF, which stands for Default Forwarding, is a PHB defined by DiffServ that provides best-effort service for unmarked traffic. DF is marked by setting the DSCP value to 000000, which corresponds to decimal 078.
AF11, which stands for Assured Forwarding class 1 low drop probability, is another PHB defined by DiffServ, but it provides lower priority than EF and AF31. AF11 is marked by setting the DSCP value to 001010, which corresponds to decimal 1078.
References: Differentiated services - Wikipedia, Solved: Cisco VoIP Phone traffic marking - Cisco Community
質問 # 41
Review the exhibit.
Referring to the exhibit, which two Ericsson routers support the 100GE interface? (Choose two.)
- A. Router 6672
- B. Router 6273
- C. Router 6471
- D. Router 6675
正解：A、D
解説：
Explanation
Referring to the exhibit, the two Ericsson routers that support the 100GE interface are Router 6675 and Router
6672. The 100GE interface is a high-speed Ethernet interface that operates at 100 gigabits per second. The Ericsson Router 6000 series is a family ofrouters that provide IP transport for mobile and fixed networks. The Router 6675 is a 5G combined access and E-RAN switch with 100GE interfaces and 320Gb forwarding capacity. The Router 6672 is a high-capacity metro aggregation router with 100GE interfaces and 1.6Tb forwarding capacity12.
References: Router 6000 Series - Ericsson, New Ericsson Router 6000 series couples radio and IP transport for
5G future - Global Brands Magazine
質問 # 42
Which operating system is used in Ericsson Router 6000 products?
- A. ERS
- B. SE-OS
- C. ERS
- D. IPOS
- E. Junos
正解：A
解説：
Explanation
The operating system used in Ericsson Router 6000 products is ERS (Ericsson Router Software). ERS is based on IPOS (IP Operating System), which is a common operating system for Ericsson's IP portfolio. ERS provides advanced features and functionality for IP transport, such as MPLS, Segment Routing, QoS, IPSec, synchronization, SDN, and more. ERS also supports seamless integration with Ericsson Radio System and Ericsson Network Manager.
References: Router 6000 Series - Ericsson, Router 6675 Datasheet - Winncom
質問 # 43
Which statement is true about LDP?
- A. LDP and IGP both exchange their databases every 30 seconds.
- B. LDP and IGP both exchange their databases every 60 seconds.
- C. LDP relies on IGP for all routing-related decisions.
- D. LDP performs routing functions along with IGP.
正解：C
解説：
Explanation
LDP relies on IGP for all routing-related decisions. LDP is a protocol that distributes labels in an MPLS environment, but it does not perform any routing functions. LDP uses the underlying routing information provided by an IGP, such as OSPF or IS-IS, to forward label packets. LDP and IGP do not exchange their databases at regular intervals, but rather use hello messages to maintain adjacencies and sessions. References: Ericsson IP Networking - Routing Protocols, Label Distribution Protocol - Wikipedia
質問 # 44
For IP destinations not found in the IS-IS Level 1 database, the Level 1 router must forward packets to the nearest Level 1-Level 2 router with which set?
- A. options bit
- B. overload bit
- C. attach bit
- D. status bit
正解：C
解説：
Explanation
For IP destinations not found in the IS-IS Level 1 database, the Level 1 router must forward packets to the nearest Level 1-Level 2 router with the attach bit set. The attach bit is a flag in the IS-IS Level 1 LSP that indicates that the router is also a Level 2 router and can reach destinations outside the Level 1 area. The Level
1 router will install a default route pointing to the nearest Level 1-Level 2 router with the attach bit set. This way, the Level 1 router can forward packets to other areas without having to maintain a full Level 2 database. References: Ericsson IP Networking - Routing Protocols, Configure Attach Bit Set - Cisco
質問 # 45
What network information is, without additional configuration, shared between two iBGP neighbors by default?
- A. BGP routes learned from eBGP neighbors
- B. IP address information of loopback interfaces
- C. IP address information from all directly connected interfaces
- D. BGP routes learned from an OSPF neighbor
正解：A
解説：
Explanation
iBGP works by exchanging routing information between two or more routers within an AS. Each router sends its own routing table to its neighbors, which contains information about the networks it knows and how they can be reached from that router. By default, iBGP neighbors only share BGP routes learned from eBGP neighbors, which are routers in different ASes. This is because iBGP assumes that all routers within an AS have consistent internal routing information provided by an IGP, such as OSPF or IS-IS. Therefore, iBGP neighbors do not need to share IP address information of loopbackinterfaces or directly connected interfaces, unless explicitly configured to do so by using commands such as neighbor update-source or network.
References: iBGP Ultimate Guide | How iBGP Is Different From eBGP, Ericsson IP Networking - Routing Protocols
質問 # 46
Which action will influence BGP route selection within your AS?
- A. changing the default link metric
- B. reducing number of hops in the network
- C. changing the default value of the local preference
- D. changing the administrative distance for eBGP
正解：C
解説：
Explanation
The action that will influence BGP route selection within your AS is changing the default value of the local preference attribute. The local preference attribute is used to indicate the preference of a path among multiple paths learned from different external BGP neighbors or autonomous systems (ASes). The higher the local preference value, the more preferred the path is within your AS, and vice versa. The default value of local preference is 100, but you can change it using route maps or other configuration methods on your BGP routers. References: Ericsson IP Networking - Routing Protocols, BGP Attributes and Path Selection, BGP Local Preference Attribute: Controlling Traffic Like a Pro
質問 # 47
Within an IGP area, which two statements are correct? (Choose two.)
- A. Routers summarize information they learn from neighbors.
- B. Routers advertise information about themselves.
- C. Routers relay information delivered by neighbors.
- D. Routers discard valid but inaccurate information from neighbors.
正解：B、C
解説：
Explanation
Within an IGP area, routers advertise information about themselves and relay information delivered by neighbors. This is how link-state routing protocols such as OSPF and IS-IS work. They flood information about the network topology to all routers in the same area or domain. That information is then used to build a complete network connectivity map and to calculate the shortest path to destinations. Routers do not summarize or discard information within an area, unless they are configured to do so by some filtering mechanism. References: Ericsson IP Networking - Routing Protocols, IP Routing: ISIS Configuration Guide - IS-IS Overview and Basic Configuration
質問 # 48
An IS-IS router has been assigned the NSAP address: 49.00F0.0100.5012.3010.00.
What is the Area ID to which the router belongs?
- A. 49.00F0.0100
- B. 5012.3010.00
- C. 00F0 0100
- D. 49.00F0
正解：A
解説：
Explanation
The Area ID to which the router belongs is 49.00F0.0100. The Area ID is a variable-length field in the NSAP address that identifies the area to which the router belongs. The Area ID can be between 1 and 13 bytes long, but it must start and end with an octet (8 bits). The NSAP address is composed of three parts: the authority and format identifier (AFI), the area ID, and the system ID. The AFI is a one-octet field that indicates the format and authority of the rest of the address. The system ID is a fixed-length field of six octets that uniquely identifies the router within an area. The NSAP address also has a network selector (NSEL) field, which is a one-octet field that identifies the network layer service to which a packet should be sent. For IS-IS routers, the NSEL must always be 00.
In this question, the NSAP address is 49.00F0.0100.5012.3010.00. This means that:
The AFI is 49, which indicates a private address.
The Area ID is 00F0.0100, which is four octets long and starts and ends with an octet.
The system ID is 5012.3010, which is six octets long and identifies the router within the area.
The NSEL is 00, which indicates IS-IS.
Therefore, the answer is B.
References: Ericsson IP Networking - Routing Protocols, IS-IS NSAP address - Cisco Community, Understanding IS-IS NSAP Addresses - Todd Lammle, LLC, IS-IS - Nokia, Network service access point address - Wikipedia
質問 # 49
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更新された検証済みのECP-206問題集と解答で合格保証もしくは全額返金：https://www.goshiken.com/Ericsson/ECP-206-mondaishu.html
ECP-206のPDF問題とテストエンジンには62問があります：https://drive.google.com/open?id=1Xnz_9Sdi0Fcxvtw7movcmw3MQZyvtZtV