Chapter 23 The Internet (220-902)
Integrated Solutions
All mobile devices have an integrated e-mail client, fully configured to work within the mobile ecosystem. Apple devices, such as the iPad, enable you to create and use an iCloud account that syncs all your Apple devices. The iCloud e-mail setup process assumes you'll use iCloud for all that sending and receiving stuff and thus you have no other configuration to do. All of the IMAP,POP,SMTP,S/MIME, and so on settings happen behind the scenes. CompTIA calls this sort of lack of configuration integrated commercial provider email configuration.
Connection Concepts
Connecting to an ISP requires two things to work perfectly: hardware for connectivity, such as a modem and a working cable line; and software, such as protocols to govern the connections and the data flow (all configured in the OS) and applications to take advantage of the various TCP/IP services.
Corporate/ISP Solutions
Corporate and ISP e-mail configuration means setting up your client software to match the settings of the e-mail server software. The most popular client by far is Microsoft Outlook. Next you must add the names of the Post Office Protocol version 3 (POP3) or Internet Message Access Protocol version 4 (IMAP) server and the Simple Mail Transfer Protocol (SMTP) server (Or you might encounter Secure/Multipurpose Internet Mail Extensions [S/MIME] in place of SMTP. S/MIME offers encryption and legal signatures). The POP3 or IMAP server is the computer that handles incoming e-mail. POP3 is by far the most widely used standard, although the latest version of IMAP, IMAP4, supports features that POP3 doesn't. For example, IMAP4 enables you to search through your e-mail and find specific words. These two systems may often have the same name, or close to the same name. Your ISP should provide you with all of these settings. When you get the name of your POP3/IMAP/SMTP server, it is good to ping the name and write it down so you know the IP for later.
Internet Service Providers
Every Tier 1 and Tier2 provider leases connections to the Internet to companies called Internet service providers (ISPs). ISPs essentially sit along the edges of the Tier 1 and Tier 2 Internet and tap into the flow. In turn, you can lease connections from an ISP to get on the Internet. ISPs come in all sizes. Comcast, the cable television provider, has multiples, huge capacity connections into the Internet, enabling its millions of customers to connect from their local machines and surf the Web. Contrast Comcast with Electric Power Board (EPB) of Chattanooga, an ISP in Chattanooga, Tennessee.
AFP
Like Microsoft and SMB, Apple and developed the Apple Filling Protocol (AFP) in late 1980s to support file sharing between Mac computers on early LANs. Just like SMB, AFP survives to this days as a way for Mac OS X machines to share files with Mac new and old. AFP is also the protocol used by Mac OS X Time Machine for backing up OS X over the network due to its support for HFS+ file system particularities. Support for AFP beyond OS X is solid on Linux, but Windows lacks out-of-box support for the protocol.
Web Mail
Most people use web based emails like: Yahoo, Google Mail, Hotmail, and more. Web-based mail is great cause you can access your mail from any computer connected to the Internet.
SFTP
SFTP uses port 22 and it is nothing more than FTP running through an SSH tunnel. This can be done in a number of ways. You can, for example, start an SSH session between two computers. Then start an FTP server on one machine and an FTP client on the other and redirect the input and output of the FTP data to go through the tunnel.
PPTP VPNs
So how do we make IP addresses appear out of thin air? Microsoft got the ball rolling with point-to-point tunneling protocol (PPTP), an advanced version of PPP that handles all of this right out of the box. The only trick is the end points. In Microsoft's view, a VPN is intended for individual clients (think employees on the road) to connect back to the office network, so Microsoft places the PPTP endpoints on the client and a special remote access server program called Routing and Remote Access Service (RRAS), available on Server version of Windows. When your computer connects to the RRAS server on the private network, PPTP creates a secure tunnel through the Internet back to the private LAN. Your client takes on an IP address of that network, as if your computer were plugged into the LAN back at the office.
TCP/IP - The Common Language of the Internet
TCP/IP is the framework and language of the Internet.
Remote Desktop
While some OS include a remote desktop client, many third party remote desktop applications are also available. Most of these make use of either the Remote Desktop Protocol (RDP) or Virtual Network Computing (VNC). Windows offers an alternative to VNC: Remote Desktop Connection. Remote Desktop Connection provides control over a remote server with a fully graphical interface. If you have a technical support issue, you could simply connect to a tech using Remote Assistance. Remote Assistance enables you to give anyone control of your desktop or take control of anyone's desktop. If a user has a problem, that user can request support directly from you. With Remote Assistance, you can do anything you would do from the actual computer. You can troubleshoot some hardware configuration or driver problem. In Windows, you can turn Remote Desktop and Remote Assistance on and off via Control Panel.
The World Wide Web
This Web provides a graphical face for the Internet. Web servers (servers running specialized software) provide Web sites that you access by using the HTTP protocol on port 80 and thus get more-or-less useful information. Setting up a Web browser takes no effort. As long as the Internet connection is working, Web browsers will work automatically.
To set up and access e-mail, you have a lot of choices today. you can use the traditional corporate or ISP method that requires a dedicated e-mail application. Increasingly though, people use e-mail clients built into their devices. Finally, you can use a web based e-mail client accessible from any device.
Configuring Other Web Browsers
Two big browsers that everyone uses are: Google Chrome and Mozilla Firefox. There are pretty much the same controls in these two browsers, except that there is no applet for it in the Control Panel.
Telnet and SSH
Telnet is a terminal emulation program for TCP/IP networks that uses port 23 and enables you to connect to a server or fancy router and run commands on that machine as if you were sitting in front of it. This way, you can remotely admin a server and communicate with other servers on your network. Telnet does not allow just anyone to connect to your computer, so they would need to enter a user name and password to run Telnet. Telnet is just like FTP and all the user names and passwords are in clear text. So be cautious on what you pick. (Telnet works over LAN). If you need a remote terminal that works securely across the Internet, you need Secure Shell (SSH). If fact, today SSH has replaced Telnet is almost all places Telnet used to be popular. To the user, SSH works just like Telnet. Behind the scenes, SSH uses port 22, and the entire connection is encrypted, preventing any eavesdropping from reading your data. SSH has another cool trick, it can move files or any type of TCP/IP network traffic through its secure connection. In networking, this is called tunneling, and is the core of most secure versions of the Internet technologies such as SFTP and VPN.
Internet Tiers
The Internet is millions and millions of computers all joined together to form the largest network earth. To keep everything organized, the Internet is broken down into groups called tiers. The main tier, called Tier 1, consists of a small number of companies called Tier 1 providers. The Tier 1 providers own long-distance, high-speed fiber-optic networks called backbones. These backbones span the major cities of the earth (not all Tier backbones go to all cities) and interconnect at special locations called network access points (NAPs). Anyone wishing to connect to any of the Tier 1 providers must pay money. The Tier 1 providers do not charge each other to connect. Tier 2 providers own smaller, regional networks and must pay the Tier 1 providers. Most of the famous companies that provide Internet access to the general public are Tier 2 providers. Tier 3 providers are even more regional and connect to Tier 2 providers. The piece of equipment that makes this tiered Internet concept work is called a backbone router. Backbone routers connect to more than one other backbone router, creating a big, interwoven framework for communication.
LDAP
The Lightweight Directory Access Protocol (LDAP) enables OS and applications to access directories. If you've got a Windows Server system running Active Directory, for example, Windows uses LDAP to do anything with Active Directory. If you are sitting at a computer and add it to an Active Directory domain, Windows uses LDAP commands to update Active Directory with the computer's info.
SMB
The Server Message Block (SMB) protocol is Windows' network file and print sharing protocol. UNIX and Linux systems used a competing protocol, Network File System (NFS), but that use has declined. Today, every major OS uses SMB: Windows, Mac OS X, and Linux (using SAMBA). SMB is the protocol of choice for LAN file servers.
SNMP
The Simple Network Management Protocol (SNMP) enables remote query and remote configuration of just about anything on a network. Assuming all your computers, switches, routers, and so on, are SNMP-capable, you can use programs to query the network for an unimaginable amount of data. SNMP is a popular protocol for checking up on your network, but it is sort of a thing you won't need to use unless you are a Network+ tech
File Transfer Protocol (FTP)
Uses ports 20 and 21, and is a great way to share files between systems. FTP server software exists for most OS, so you can use FTP to transfer data between any two systems regardless of the OS. To access an FTP site, you must use an FTP client such FileZilla, although most Web browsers provide at least download support for FTP. Although you can use a Web browser, all FTP sites require you to log on. You Web browser automatically assumes that you want to log in as "anonymous". If you want to log on as a specific user, you have to add your user name to the URL. (Instead of typing ftp://ftp.example.com, you would type ftp://[email protected]) An anonymous log on works fine for must public FTP sites. Many techs prefer to use third-party programs such as FileZilla or Cyberduck on Mac OS X for FTP access because these third-party applications can store user name and password settings. This enables you to access the FTP site more easily later. Keep in mind that all of the passwords and usernames you type in are in clear text. So do not choose the same username and password that you use for other things (like your online bank account).
Virtual Private Networks
VPNs are great because they are private and secure. An encrypted tunnel requires endpoints- the ends of the tunnel where the data is encrypted and decrypted. VPNs require a protocol that itself uses one of the many tunneling protocols available and adds the capability to ask for an IP address from a local DHCP server to give the tunnel and IP address that matches the subnet of the local LAN. The connection keeps the IP address to connect to the Internet, but the tunnel endpoints must act like NICs.
Configuring Interent Explorer
Web browsers are highly configurable. On most Web browsers, you can set default font size, choose whether to display graphics, and adjust several other settings. To change this, go to the Internet Options Control Panel applet or under the Tool menu in Internet Explorer. The General tab has the most basic features of Internet Explorer: the home page, tab management, your browsing history, searching, and other appearance controls. If you want to delete or change how Internet Explorer stores the Web sites you've visited, use this tab. The Security tab enables you to set how Internet Explorer safeguards your Web browsing. Each setting can be adjusted for a particular zone, such as the Internet, your local intranet, trusted sites, and restricted sites. You can configure which Web sites fall into which zones. Once you've picked a zone to control, you can set Internet Explorer's security level. The Privacy tab works a lot like the Security tab, except it controls privacy matters, such as cookies, location tracking, pop-ups, and whether browser extensions will run in private browsing mode. Go here if you don't like the idea of Web sites tracking your browsing history (through cookies and other things, too, like authenticate users). The Content tab controls what your browser will and will not display. This time however, it enables you to gate access to insecure or objectionable site- a practice called content filtering- using certificates and a parental control tool called Family Safety, which lets system admins restrict Web, game, and app usage and even controlling when an account can log in. The Connection tab lets you set up a VPN or Proxy. Many corporations use a proxy server to filter employee Internet access, and when you are on their corporate network, you need to set your proxy settings within the Web browser. A proxy server is software that enables multiple connections to the Internet to go through one protected computer. Applications that want to access Internet resources send requests to the proxy server instead of trying to access the Internet directly, which both protects the client computers and enables the network admin to monitor and restrict Internet access. Each application must therefore be configured to use the proxy server. The Programs tab in Internet Options contains settings for your default Web browser, any add ons you use, and how other programs deal with HTML files and e-mail messages. The Advanced tab does exactly what it sounds like: lists a bunch of advanced options that you can turn off and on with the check of a box. The available options include accessibility, browsing, international, and most importantly, security settings. From here you can control how Internet Explorer checks Web site certificates, among many other settings.
Unified Internet Accounts
When I log into my Windows 10 desktop computer, I use my Microsoft account, a fully functional e-mail account hosted by Hotmail. There is no configuration from a user's or tech's perspective. Microsoft and CompTIA calls this Live sign in.
Voice over IP (VoIP)
You can use Voice over IP (VoIP) to make voice calls over your computer network. VoIP works with every type of high-speed Internet connection, from DSL, to cable to satellite. VoIP doesn't use a single protocol, it uses a collection of protocols that make phone calls over the data network possible. The most common VoIP application protocol is Session Initiation Protocol (SIP), but popular VoIP applications such as Skype are completely proprietary. A key to remember when installing and troubleshooting VoIP is that low network latency is more important than high network speed. Latency is the amount of time a packet takes to get to its destination and is measured in milliseconds. VoIP isn't configured to your computer, either. It can completely replace your old copper phone line. Two popular ways to set up a VoIP system are to either use dedicated VoIP phones, or use a small VoIP phone adapter that can interface with your existing analog phones. True VoIP has RJ-45 connectors that plug directly into the network and offer advanced features such as HD-quality audio and video calling. Unfortunately, these phones require a complex and expensive network to function, with puts them out of reach with most home users. For home users, it's much more common to use a VoIP phone adaptor to connect to your old-school analog phones.
