D-Link Router DIR-857 User Manual

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Section 6 - Troubleshooting
Troubleshooting
This chapter provides solutions to problems that can occur during the installation and operation of the DIR-857. Read the following descriptions 
if you are having problems. (The examples below are illustrated in Windows
® XP. If you have a different operating system, the screenshots on your 
computer will look similar to the following examples.)
1. Why can’t I access the web-based configuration utility?
When entering the IP...

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• Configure your Internet settings: • Go to  Start >  Settings >  Control Panel. Double-click the  Internet Options Icon. From the  Security tab, click the button to restore 
the settings to their defaults.
•  Click the  Connection tab and set the dial-up option to Never Dial a Connection. Click the LAN Settings button. Make sure nothing 
is checked. Click OK. 
•  Go to the Advanced tab and click the button to restore these settings to their...

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3. Why can’t I connect to certain sites or send and receive emails when connecting through my router? 
If you are having a problem sending or receiving email, or connecting to secure sites such as eBay, banking sites, and Hotmail, we suggest lowering 
the MTU in increments of ten (Ex. 1492, 1482, 1472, etc). 
Note: AOL DSL+ users must use MTU of 1400. 
To find the proper MTU Size, you’ll have to do a special ping of the destination you’re trying...

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You should start at 1472 and work your way down by 10 each time. Once you get a reply, go up by 2 until you get a fragmented packet. Take that 
value and add 28 to the value to account for the various TCP/IP headers. For example, lets say that 1452 was the proper value, the actual MTU size 
would be 1480, which is the optimum for the network we’re working with (1452+28=1480). 
Once you find your MTU, you can now configure your router with the...

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Appendix A - Wireless Basics
D-Link  wireless  products  are  based  on  industry  standards  to  provide  easy-to-use  and  compatible  high-speed  wireless  connectivity  within  your 
home, business or public access wireless networks. Strictly adhering to the IEEE standard, the D-Link wireless family of products will allow you to 
securely access the data you want, when and where you want it. You will be able to enjoy the freedom that wireless networking delivers.
A...

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How does wireless work? 
  
Wireless works similar to how cordless phone work, through radio signals to transmit data from one point A to point B. But wireless technology has 
restrictions as to how you can access the network. You must be within the wireless network range area to be able to connect your computer. There 
are two different types of wireless networks: Wireless Local Area Network (WLAN) and Wireless Personal Area Network (WPAN)....

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Where is wireless used? 
  
Wireless technology is expanding everywhere not just at home or office. People like the freedom of mobility and it’s becoming so popular that more 
and more public facilities now provide wireless access to attract people. The wireless connection in public places is usually called “hotspots”.
Using a D-Link Cardbus Adapter with your laptop, you can access the hotspot to connect to Internet from remote locations like:...

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Appendix A - Wireless Basics
There are basically two modes of networking:  • Infrastructure – All wireless clients will connect to an access point or wireless router.
•  Ad-Hoc – Directly connecting to another computer, for peer-to-peer communication, using wireless network adapters on each 
computer, such as two or more DIR-857 wireless network Cardbus adapters.
An Infrastructure network contains an Access Point or wireless router. All the wireless devices, or clients,...

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Appendix B - Networking Basics
Networking Basics
Check your IP address
After  you  install  your  new  D-Link  adapter,  by  default,  the TCP/IP  settings  should  be  set  to  obtain  an  IP  address  from  a  DHCP  server  (i.e.  wireless 
router) automatically. To verify your IP address, please follow the steps below.
Click on Start > Run. In the run box type cmd and click OK. (Windows® 7/Vista® users type cmd in the Start Search box.)
At the prompt, type ipconfig and...

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Appendix B - Networking Basics
Statically Assign an IP address
If you are not using a DHCP capable gateway/router, or you need to assign a static IP address, please follow the steps below:
Step 1
Windows® 7 - Click on Start > Control Panel > Network and Internet > Network and Sharing Center.
Windows Vista® - Click on Start > Control Panel > Network and Internet > Network and Sharing Center > Manage Network Connections.
Windows XP - Click on Start > Control Panel > Network...