Network+ N10-008 / Chapter 1 "Introduction to Networks"

What are the different types of servers?

•File Server: Stores and dispenses files •Mail Server: The network's post office; handles email functions •Print Server: Manages printers on the network •Web Server: Manages web-based activities by running Hypertext Transfer Protocol Secure (HTTPS) for storing web content and accessing web pages •Fax Server: The "memo maker" that sends and receives paperless faxes over the network •Application Server: Manages network applications •Telephony Server: Handles the call center and call routing and can be thought of as a sophisticated network answering machine •Proxy Server: Handles tasks in the place of other machines on the network, particularly an Internet connection •DHCP Sever: Issues IP addresses to client machines •DNS Server: Resolves FQDN to IP addresses

What is a Personal Area Network (PAN)?

•For close proximity connections there are PANs, or personal area networks. •These are seen with smartphones and laptops in a conference room where local connections are used to collaborate and send data between devices. •While a PAN can use a wired connection such as Ethernet or USB, it is more common that short distance wireless connections are used such as Bluetooth, infrared, or ZigBee. •PANs are intended for close proximity between devices such as connecting to a projector, printer, or a coworker's computer, and they extend usually only a few meters.

Service-Related Entry Points

•In the networking world, there are clearly defined boundaries where one entity hands off a connection to another. •These are common when connecting to a service provider's or carrier's WAN circuit. The service entry point defines the point of responsibility. •The common term used is the demarcation point, or demarc for short. •A carrier will usually terminate with a piece of equipment called a smart jack that allows them to run diagnostics up to the physical point where the customer's network connects.

What is a ring topology?

•In this type of topology, each computer is directly connected to other computers within the same network. •The problem is, the ring topology has a lot in common with the bus topology because if you want to add to the network, you have no choice but to break the cable ring, which is likely to bring down the entire network! •Examples: •802.5 Token Ring •FDDI

What is a mesh topology?

•In this type of topology, you'll find that there's a path from every machine to every other one in the network. •Often, hybrid mesh topology networks will have quite a few connections between certain places to create redundancy (backup). •Types: •Partial •Full •Hybrid

Virtual Networking

•It is now common to provide networking services without deploying a hardware switch or router; it is all done in software. •Virtualized servers do not have the means for inserting a hardware network interface card since they only exist in software. •A virtual network interface card (vNIC) is installed to connect the virtual device to the hypervisor, and from there, out to the LAN. •Network function virtualization (NFV) is the process of taking networking functions such as routers, switches, firewalls, load balancers, and controllers and virtualizing them. This process allows all of these functions to run on a single device.

What is Mulitprotocol Label Switching (MPLS)?

•MPLS has become one of the most innovative and flexible networking technologies on the market, and it has some key advantages over other WAN technologies: •Physical layout flexibility •Prioritizing of data •Redundancy in case of link failure •One-to-many connection •MPLS is a switching mechanism that imposes labels (numbers) to data and then uses those labels to forward data when it arrives at the MPLS network. •The labels are assigned on the edge of the MPLS network and forwarding inside the MPLS network (cloud) is done solely based on labels through virtual links instead of physical links. •Prioritizing data is a huge advantage; for example, voice data could have priority over basic data based on the labels. •Since there are multiple paths for the data to be forwarded through the MPLS cloud, there's even some redundancy provided as well.

What is a Wide Area Network (WAN)?

•Most common example: The Internet •Here's a list of some of the important ways that WANs are different from LANs: •WANs usually need a router port or ports. •WANs span larger geographic areas and/or can link disparate locations. •WANs are usually slower. •We can choose when and how long we connect to a WAN. A LAN is all or nothing—our workstation is connected to it either permanently or not at all, although most of us have dedicated WAN links now. •WANs can utilize either private or public data transport media such as phone lines.

What are the most common types of network topologies?

•Most common types of topologies: •Bus •Star/hub-and-spoke •Ring •Mesh •Point-to-point •Point-to-multipoint •Hybrid

What is a network segment?

•Network Segments refer to the small sections of the network that workstations and servers are organized into different parts of the network.

What is a network backbone?

•Network backbone is usually the large bandwidth, high-speed part of your architecture.

What's a server?

•Servers are powerful computers. •Servers must have considerably superior CPUs, hard-drive space, and memory—a lot more than a simple client's capacity—because they serve many client machines and provide any resources they require. •In a good design that optimizes the network's performance, servers are highly specialized and are there to handle one important labor-intensive job. •Sometimes they handle multiple tasks. •Whether servers are designated for one job or are network multitaskers, they can maintain the network's data integrity by backing up the network's software and providing redundant hardware (for fault tolerance).

Service Provider Links

•Service providers are Internet service providers and cable and telephone companies that provide networking services. • •There are many different technologies used to provide these services such •Satellite •Telephony •Broadband cable •Leased lines •Metro Optical Network

What is Multipoint Generic Encapsulation (MGRE)?

•The Multipoint Generic Routing Encapsulation (mGRE) protocol refers to a carrier or service provider offering that dynamically creates and terminates connections to nodes on a network. mGRE is used in Dynamic Multipoint VPN deployments. • •The protocol enables dynamic connections without having to pre-configure static tunnel endpoints. • •The protocol encapsulates user data, creates a VPN connection to one or many nodes, and when completed, tears down the connection.

What is a bus topology?

•The bus topology consists of two distinct and terminated ends, with each of its computers connecting to one unbroken cable running its entire length. •10Base2 and 10Base5 •"T" connectors or Vampire taps •Bus terminators. •Coaxial cable

What's the difference between physical and logical topologies?

•The physical topology of a network is a type of map of where devices are located. •The logical topologies delineate exactly how data moves through the network.

What are the two types of network types?

•There are two main network types you need to know about: peer-to-peer and client-server. •Computers connected together in peer-to-peer networks do not have any central, or special, authority—they're all peers, meaning that when it comes to authority, they're all equals. •Client-server networks are pretty much the polar opposite of peer-to-peer networks because in them, a single server uses a network operating system for managing the whole network.

What is a host?

•This can be kind of confusing because when people refer to hosts, they really can be referring to almost any type of networking devices—including workstations and servers. •Host means any network device with an IP address. •A host is also a computer or server that hosts resources for the network users.

What are the three most common network components?

•Workstations •Servers •Hosts

What's a workstation?

•Workstations are often employed as systems that end users use on a daily basis. •The terms workstation, client, and host can sometimes be used interchangeably. •A node is any addressable device on the network.

What is a Software-Defined Wide Area Network (SDWAN)?

•A software-defined wide area network (SDWAN) is a virtual WAN architecture that uses software to manage connectivity, devices, and services and can make changes in the network based on current operations. • •SDWANs integrate any type of transport architectures such as MPLS, LTE, and broadband Internet services to securely connect users to applications. •The SDWAN controller can make changes in real time to add or remove bandwidth or to route around failed circuits. •SDWANs can simplify wide area networking management and operations by decoupling the networking hardware from its control mechanism.

What is a star topology?

•A star (hub-and-spoke) topology's computers are connected to a central point with their own individual cables or wireless connections. •You'll often find that central spot inhabited by a device like a hub, a switch, or an access point. •Advantages: •New stations can be added or moved easily and quickly. •A single cable failure won't bring down the entire network. •It's relatively easy to troubleshoot. •Disadvantage: •The total installation cost can be higher because of the larger number of cables, even though prices are becoming more competitive. •It has a single point of failure—the hub or other central device.

What is a Storage Area Network (SAN)?

•A storage area network (SAN) is designed for, and used exclusively by, storage systems. •SANs interconnect servers to storage arrays containing centralized banks of hard drive or similar storage media. •SANs are usually only found in data centers and do not mix traffic with other LANs. •The protocols are designed specifically for storage with Fibre Channel being the most prevalent along with iSCSI. •The network hardware is different from LAN switches and routers and are designed specifically to carry storage traffic.

What is an intenetwork?

•An internetwork is a type of LAN and/or WAN that connects a bunch of networks, or intranets. •We get the word Internet from the term internetwork. •In an internetwork, hosts still use hardware addresses to communicate with other hosts on the LAN. •However, they use logical addresses (IP addresses) to communicate with hosts on a different LAN (on the other side of the router). •Routers connect different networks to create either intranets, extranets, or the internet. •All of this is internetworking.

What is point-to-point topology?

•As its name implies, in a point-to-point topology you have a direct connection between two routers or switches, giving you one communication path. •The routers in a point-to-point topology can be linked by a serial cable, making it a physical network, or if they're located far apart and connected only via a circuit within a Frame Relay or MPLS network, it's a logical network instead.

What's a Network?

• Network means two or more connected computers that can share resources such as data and applications, office machines, an Internet connection, or some combination of these.

What is a Campus Area Network (CAN)?

•A CAN, or campus area network, covers a limited geographical network such as a college or corporate campus. •The CAN typically interconnects LANs in various buildings and offers a Wi-Fi component for roaming users. •A campus area network is between a LAN and WAN in scope. They are larger than a local area network (LAN) but smaller than a metropolitan area network (MAN) or wide area network (WAN). •Most CANs offer Internet connectivity as well as access to data center resources.

What is a hybrid topology?

•A combination of two or more types of physical or logical network topologies working together within the same network.

Local Area Network (LAN)

•A local area network (LAN) is usually restricted to spanning a particular geographic location such as an office building, a single department within a corporate office, or even a home office. •It's best to split a big LAN into smaller logical zones known as workgroups to make administration easier. •With smaller, individual-yet-connected groups, the users on each LAN enjoy much faster response times when accessing resources, and administrative tasks are a lot easier too. •Larger workgroups run more slowly because there's a legion of hosts within them that are all trying to get to the same resources simultaneously. •The router shown in the graphic separates the workgroups while still allowing access between them.

What is a Metropolitan Area Network (MAN)?

•A network covering a metropolitan area used to interconnect various buildings and facilities usually over a carrier provided network. •Think of a MAN as a concentrated WAN and you've got it. •MANs typically offer high speed interconnections using in-ground fiber optics and can be very cost effective for high-speed interconnects.

What is point-to-multipoint topology?

•A point-to-multipoint topology consists of a succession of connections between an interface on one router and multiple destination routers—one point of connection to multiple points of connection. •Each of the routers and every one of their interfaces involved in the point-to-multipoint connection are part of the same network.