102-500 Premium Exam Questions

The traceroute program can be used to determine the routing path to a given destination by sending packets with incrementing TTL values and recording the source of the ICMP time exceeded messages. This way, it can show the intermediate hops and the round-trip times for each packet. The other programs have different purposes: dig is used to query DNS servers, netstat is used to display network connections and statistics, ping is used to test the reachability of a host by sending ICMP echo requests and measuring the response time, and route is used to manipulate the routing table. References:

LPI 102-500 Exam Objectives, Topic 110: Network Fundamentals, Weight: 4, 110.3 Basic network troubleshooting

LPI 102-500 Study Guide, Chapter 10: Network Fundamentals, Section 10.3: Basic Network Troubleshooting, Page 125-126

The parameter that must be passed to ifconfig to activate a previously inactive network interface is up. The up parameter tells the kernel to activate the network interface and allow it to send and receive packets. The opposite of up is down, which deactivates the network interface. The up parameter is part of the topic 109.2: Basic network configuration, which is one of the objectives of the LPI Linux Administrator - 102 exam12. References: 1: https://learning.lpi.org/en/learning-materials/102-500/  2: https://www.lpi.org/our-certifications/exam-102-objectives/

 The keywords dns and files can be used in the /etc/nsswitch.conf file to specify a source for host name lookups. The keyword dns means that the system will use the Domain Name System (DNS) to resolve host names to IP addresses. The keyword files means that the system will use the local /etc/hosts file to resolve host names to IP addresses. The order of the keywords on the line determines the order in which the sources will be queried. For example, the following line in /etc/nsswitch.conf:

hosts: files dns

means that the system will first check the /etc/hosts file for a matching host name, and if not found, it will query the DNS servers configured in /etc/resolv.conf. The other keywords in the question are not valid for the hosts database. The keyword resolv is used for the services database, which contains network service names and port numbers. The keyword remote is not a standard keyword, but it may be used by some applications to implement their own name service providers. The keyword hosts is the name of the database itself, not a source for it. References:

[LPI Linux Administrator - Exam 102 Objectives - Topic 109: Networking Fundamentals]

nsswitch.conf(5) - Linux manual page

What is the /etc/nsswitch.conf file in Linux – TecAdmin

The keyword files must be listed in the hosts option of the Name Service Switch configuration file in order to make host lookups consult the /etc/hosts file. The files service specifies that the local files, such as /etc/hosts, should be used as a source of information. The order of the services on the line determines the order in which those services will be queried, in turn, until a result is found. For example, if the hosts option is set to:

hosts: files dns

then the /etc/hosts file will be searched first, and if no match is found, the DNS server will be queried next. If the hosts option is set to:

hosts: dns files

then the DNS server will be queried first, and if no match is found, the /etc/hosts file will be searched next. References:

LPI 102-500 Exam Objectives, Topic 110: Network Fundamentals, Weight: 4, 110.3 Basic network troubleshooting

LPI 102-500 Study Guide, Chapter 10: Network Fundamentals, Section 10.3: Basic Network Troubleshooting, Page 125-126

nsswitch.conf: Name Service Switch configuration file