cisco ccna vs comptia network+

cisco ccna vs comptia network+.The purpose of this section is to explore all aspects of how two hosts communicate with each other. The /gig DNS is based on a hierarchical architecture called a domainnamespace. The DNS hierarchy is a tree-like structure, where each leaf of the tree represents a specific resource, uniquely identified by a Fully Qualified Domain Name (FQDN).The FQDN is made up of individual names linked together in the tree structure, starting with the name of the leaf and ending at the root of the tree.An example of a DNS domain name space is shown in Figure 1-63. The host www.epubit.com FQDN consists of the top-level domain ( TLD) (com), the second-level domain (epubit), and the resource name or host name (www) (that is, the name of the server providing WWW services), in that order, starting at the root of the tree. As another example, within the same second-level domain (epubit.com) there is another resource ------------------------ a server named tools, whose FQDN will be tools.epubit.comoFigure 1.63 DNS Domain Name Space75 Chapter 1 Network Protocols and Network Device BasicsEcho Request message) is delivered to the destination remote host, packet drop processing has been done. When an IP packet with an "expired" TTL field value is received, the router generates an ICMP Time Exceeded message. The router discards the "expired" packet and sends back an Exceed inTransit message (type 11, code 0), which is a type of ICMP expiration message, to its source IP address.1.6 Domain Name System (DNS) 76The types of domain names are shown in Table l.l8. Table 1-18 Domain NamesType PurposeRoot Domain The root domain is usually denoted by a dot (.) is usually denoted by a dot (.) and refers to the top of the DNS hierarchy