DNS Message Format (25.1.3) The DNS server stores different types of resource records that are used to resolve names. These records contain the name, address, and type of record. Some of these record types are as follows: • A – An end device IPv4 address • NS – An authoritative name server • AAAA –…
Author: examcert
IP Addressing Services – 100-150 Exam Guide
Objectives Upon completion of this chapter, you will be able to answer the following questions: • How does DNS operate? • How does DHCP operate? Key Terms This chapter uses the following key terms. You can find the definitions in the Glossary. Domain Name System (DNS) Dynamic Host Configuration Protocol (DHCP) fully-qualified domain names (FQDNs)…
Address Resolution Summary
Address Resolution Summary (24.2) The following is a summary of each topic in the chapter and some questions for your reflection. What Did I Learn in this Module? (24.2.1) To send a packet to another host on the same local IPv4 network, a host must know the IPv4 address and the MAC address of the…
Removing Entries from an ARP Table
Removing Entries from an ARP Table (24.1.6) For each device, an ARP cache timer removes ARP entries that have not been used for a specified period of time. The times differ depending on the operating system of the device. For example, newer Windows operating systems store ARP table entries between 15 and 45 seconds, as…
Video – ARP Operation – ARP Reply
Video – ARP Operation – ARP Reply (24.1.4) Only the device with the target IPv4 address associated with the ARP request will respond with an ARP reply. The ARP reply is encapsulated in an Ethernet frame using the following header information: • Destination MAC address — This is the MAC address of the sender of…
ARP Functions – 100-150 Exam Guide
ARP Functions (24.1.2) When a packet is sent to the data link layer to be encapsulated into an Ethernet frame, the device refers to a table in its memory to find the MAC address that is mapped to the IPv4 address. This table is stored temporarily in RAM memory and called the ARP table or…
Address Resolution – 100-150 Exam Guide
Objectives Upon completion of this chapter, you will be able to answer the following questions: • What is the purpose of ARP? Key Terms This chapter uses the following key terms. You can find the definitions in the Glossary. ARP table ARP cache Introduction (24.0) Webster here again! I have another friend to introduce to…
IPv4 Address Structure Summary
IPv4 Address Structure Summary (23.2) The following is a summary of each topic in the chapter and some questions for your reflection. What Did I Learn in this Module? (23.2.1) An IPv4 address is a 32-bit hierarchical address that is made up of a network portion and a host portion. When determining the network portion…
The Prefix Length – 100-150 Exam Guide
The Prefix Length (23.1.3) Expressing network addresses and host addresses with the dotted decimal subnet mask address can become cumbersome. Fortunately, there is an alternative method of identifying a subnet mask, a method called the prefix length. The prefix length is the number of bits set to 1 in the subnet mask. It is written…
IPv4 Address Structure – 100-150 Exam Guide
Objectives Upon completion of this chapter, you will be able to answer the following questions: • What is the structure of an IPv4 address including the network portion, the host portion, and the subnet mask? Key Terms This chapter uses the following key terms. You can find the definitions in the Glossary. prefix length Introduction…