CompTIA A_ Certification All-In-One Exam Guide, Seventh Edition - Michael Meyers [446]
Figure 25-27 Changing the username and password
Disabling DHCP If you are configuring a router for a small office, the router’s built-in DHCP server might conflict with a domain controller on your network. These conflicts, although not dangerous, can cause a lot of frustration and shouting as everyone’s network connections stop working. To avoid this blow to inter-office relations, you should disable the DHCP server in the router before you plug it into the network. To do this, use a separate computer such as a laptop, or unplug your computer from the wall and plug it into the new router to log in. Once on the configuration screen, you will see a configuration page similar to the one in Figure 25-28.
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CAUTION Once the DHCP server is disabled, the router will no longer hand out IP addresses, so you must make sure that the router’s IP address is in the correct subnet of your office’s LAN. If it isn’t, you need to change it before you disable DHCP.
On my router, all that is needed is to enter the new address and subnet at the top of the screen shown in Figure 25-28. If you are unsure what address you need, ask your network administrator or CompTIA Network+ tech. Once you have the router’s IP address taken care of, all you need to do is click the Disable radio button and save the settings. Now you can safely plug your router into the LAN without risking the ire of Internet-less coworkers.
Figure 25-28 Configuring DHCP server
Setting Static IP Addresses With that all taken care of, let’s look at setting up the router to use a static IP address for the Internet or WAN connection. In most cases, when you plug in the router’s Internet connection, it receives an IP address using DHCP just like any other computer. Of course, this means that your Internet IP address will change from time to time, which can be a bit of a downside. This does not affect most people, but for some home users and businesses, it can present a problem. To solve this problem, most ISPs enable you to order a static IP. Once your ISP has allocated you a static IP address, you must manually enter it into your router. You do this the same way as all the previous changes you’ve just looked at. My router has a WAN configuration tab where I can enter all the settings that my ISP has provided me (Figure 25-29). Remember, you must change your connection type from Automatic/DHCP to Static IP to enter the new addresses.
Updating Firmware
Routers are just like any other computer in that they run software—and software has bugs, vulnerabilities, and other issues that sometimes require updating. The router manufacturers call these “firmware updates” and make them available on their Web sites for easy download. To update a modern router, you simply have to download the latest firmware from the manufacturer’s Web site to your computer. Then you enter the router’s configuration Web page and find the firmware update screen. On my router, it looks like Figure 25-30. From here, just follow the directions and click Update. A quick word of caution: Unlike a Windows update, a firmware update gone bad can brick your router. In other words, it can destroy the hardware and make it as useful as a brick sitting on your desk. This rarely happens, but you should keep it in mind when doing a firmware update.
Figure 25-29 Entering a static IP address
Figure 25-30 Firmware update page
Internet Software Tools
Once you’ve established a connection between the PC and the ISP, you can do nothing on the Internet without applications designed to use one or more TCP/IP services, such as Web browsing and e-mail. TCP/IP has the following commonly used services:
World Wide Web (HTTP and HTTPS)
E-mail (POP and SMTP)
Newsgroups
FTP
Telnet
VoIP