Internet Connection Troubleshooting

Identifying and Resolving Slow Connection Issues

Here are some key ways to identify and resolve slow connection issues:

To check the network utilization, go to Task Manager and then to the Networking tab. Usage is typically low or near zero. Big spikes indicate something is abusing the network.To identify processes that may extending the network usage, use programs like netstat. Type netstat in the command prompt and then turn off suspect processes using the Task Manager. You can also set up Quality of Service (QoS) in a router if other users are causing excessive network usage. Refer to the router manufacturer’s instructions to set priorities.

Internet Summary

You have reached the end of the lesson on the Internet. Before taking your exam, review your notes and any lesson segments that need further attention.Key concepts from this lesson are:

  • Several options exist for wireless connection to the Internet: cellular LAN, Wi-Fi, and satellite communications. Windows Internet Connection Sharing (ICS) can also be used to connect one computer to the Internet using another computer’s Internet connection. ICS converts the Internet-connected computer into a router that has a network address translation (NAT) and a Dynamic Host Configuration Protocol (DHCP) server.
  • There are two forms of data networking communications: TCP and UDP. TCP provides the most reliable connection; therefore, most Internet applications run using TCP. UDP is connectionless – data is sent without confirmation of its reception, but applications using this protocol can run faster. Ports are used to direct data packets to the appropriate application in the server.
  • There are three primary protocols used in email: SMTP for sending, and POP3 and IMAP4 for receiving.
  • FTP allows a user to transfer data between two systems, regardless of the operating systems in use. It uses TCP port 20 for the data channel and port 21 for the command (control) channel.
  • Telnet, Secure Shell (SSH), and Windows Remote Desktop protocol (RDP) can all be used to access computer systems remotely.
  • VPN is another way to work remotely. Although the Internet is being used with VPN, VPN encapsulates the public data packets in a virtual tunnel that shields the packets so that the only devices that can read them are the client and those at the office (network).
  • The two biggest issues connecting to the Internet are DNS issues and issues with slow connections. The command prompt can be used to analyze both issues. Netstat is one command that is useful to diagnose network usage.

Finding DNS Issues

Use command prompt for Windows or Terminal for Mac to troubleshoot DNS issues.

Ping Server

To check DNS, ping a popular website like google:

ping google.com
Response:
PING google.com (172.217.8.174): 56 data bytes
64 bytes from 172.217.8.174: icmp_seq=0 ttl=53 time=36.336 ms
64 bytes from 172.217.8.174: icmp_seq=1 ttl=53 time=36.939 ms
64 bytes from 172.217.8.174: icmp_seq=2 ttl=53 time=36.137 ms64 bytes from 172.217.8.174: icmp_seq=3 ttl=53 time=35.105 ms
64 bytes from 172.217.8.174: icmp_seq=4 ttl=53 time=34.771 ms
64 bytes from 172.217.8.174: icmp_seq=5 ttl=53 time=35.745 ms64 bytes from 172.217.8.174: icmp_seq=6 ttl=53 time=40.113 ms
64 bytes from 172.217.8.174: icmp_seq=7 ttl=53 time=35.555 ms

--- google.com ping statistics ---
8 packets transmitted, 8 packets received, 0.0% packet loss
round-trip min/avg/max/stddev = 34.771/36.338/40.113/1.565 ms

If an IP address is returned, then DNS is fine. Otherwise, there is a problem.

To troubleshoot DNS, type > ipconfig 

Find the DNS server to confirm that there is an IP address by typing nslookup. The DNS server name and IP address should display.To test a server, type server 8.8.4.4. This should resolve to Google’s public DNS.

To clear the DNS cache, type ipconfig/displaydns to display what is stored. Then type ipconfig/flushdns to clear all DNS resolutions from the computer’s cache.

Use a public DNS server if your DNS server is not functioning. In the Control Panel, go to Network and Internet, then right-click to get on Network Connections for Properties. Enter 8.8.8.8 to use Google’s public DNS server