Network Connection Troubleshooting Steps -- WiFi and Ethernet

Overview

This article is provide you the steps to troubleshoot network connection for WiFi and Ethernet port issues.

Procedure

Steps for Ethernet (hard wire network connection):

• There is one active port per student. In a double there is usually Two duplex jacks. They are typically labeled “A, B & C, D” or “1,2 & 3,4”. Normally A is reserved for a telephone (rarely used). B&D are network and C is a spare. 

• When you plug in your device, please wait at least one minute to give your device time to connect.

• You should plug your device directly into the wall port and make sure it is setup to use DHCP and you should remove any DNS servers that are setup so your DNS will will use one of the RPI's DNS servers.

Windows

• • 1. In the Windows search bar, type in Run, and hit <Enter>.
    2. In the Run dialog box type cmd and click OK.
    3. At the command prompt type in ipconfig /flushdns, and then press <Enter>.
    4. Next, in the command prompt type in ipconfig /release, and then press <Enter>.
    5. Next, in the command prompt type in ipconfig /renew, and then press <Enter>.

Mac

• 1. 1. First, Navigate to Applications, in Utilities select Terminal.
     2. To Flush DNS, type in the following command and hit enter.
        • For Mac OS X Yosemite and later, type: sudo killall -HUP mDNSResponder
        • For Mac OS X Yosemite v10.10 -> v10.10.3, type sudo discoveryutil mdnsflushcache
        • For Mac OS X Mavericks, Mountain Lion, & Lion, type: sudo killall -HUP mDNSResponder
        • For Mac OS X Snow Leopard, type: sudo dscacheutil -flushcache
     3. Next, choose Apple menu, select System Preferences, then click Network.
     4. In the list at the left, select the network service that needs a renewed IP address.
     5. Click Advanced, click TCP/IP, then click Renew DHCP Lease.
• When you connect your device(s) via Ethernet, do the connectivity lights activate at all? And if so, what color lights, and are they steady or blinking lights?

• Have you tested the connections with multiple devices, or only one?

Additional Steps for Ethernet and WiFi connections:

Forgetting the WPA2 network (This will allow the RCS username and password login prompt to appear)

Windows

1. Click the Network icon on the lower right corner of your screen.
2. Click Network settings.
3. Click Manage Wi-Fi settings.
4. Under Manage known networks, click the network you want to delete.
5. Click Forget. The wireless network profile is deleted.
6. Selected wpa2 wireless connection in the lower right corner of your windows 10 taskbar and choose wpa2 and connect.  A login screen should appear to type your RCS username and password. 

Mac

1. Open System Preferences.
2. Click Network, then Advanced…
3. Select a network from the list and click the “-” icon just below the list to forget/remove it.

Removing Password Credentials

Windows

1. Click on the WiFi networks icon located on the right side of the taskbar
2. Click "Networks settings"
3. Click Manage Wi-Fi settings
4. Choose WPA2 and click on "Forget"
5. Click the WiFi networks icon again and then choose WPA2 and type in your RCS username and password.
6. Click Connect.

Mac

Updating your Network Drivers in Windows

1. Open Start.
2. Search for Device Manager and click the top result to open the app.
3. Expand the Network adapters branch.
4. Right-click the adapter with the problem and select the Update driver option. ...
5. Click the Search automatically for update driver software option.
6. Restart your computer

How do I prioritize network connections in Windows?

 

If you want to change the order in which Windows uses network adapters, do the following:

1. Open Settings.
2. Click on Network & Internet.
3. Click on Status. ( In Windows 11, Select Advanced Network Settings)
4. Click the Change Adapter options item. ( In Windows 11, Select More network adapter options)
5. Right-click the network adapter you want to prioritize, and select Properties.
6. Left-click on Internet Protocol Version 4 (TCP /IPv4) and hit Properties
7. Once in the Properties menu, select Advanced
8. Uncheck the Automatic metric box and in the Interface Metric section, enter 5. This will prioritize the network. Click OK and exit out of the prompts.

Manage Wireless Adapter Power Settings

Windows

1. Click on the link for more info, Wireless Adapter: Power Management Settings

DNS Configuration -- should be set to Obtain DNS server address automatically

Windows

1. Control Panel - Network and and Internet - Network and Sharing Center

2. On the left click on Change adapter settings

3. Double click on WiFi - click Properties

4. Highlight Internet Protocol Version 4 (TCP/IPv4) - click Properties - make sure Obtain DNS server address automatically is selected - click OK

5. Highlight Internet Protocol Version 6 (TCP/IPv6) - click Properties - make sure Obtain DNS server address automatically is selected - click OK

6. Repeat steps 4 and 5 for Ethernet Network connection

Producing the diagnostic file needed for an Administrator to review your connection

Windows

When you are having trouble connecting again, please go through the steps on the attached README_NetworkTroubleshootingSteps.txt file.  

1. After reading this file, open hddig.zip file (located at the bottom of this article) will will open in file explorer and show three files:

• • readme.txt (shows the same information as in the README_NetworkTroubleshootingSteps.txt)
  • helpdesk.txt (shows a SAMPLE OF the IPConfig file that is the diagnostic file that Help Desk needs to determine the WiFi or Ethernet connection) The next step will show you how to run on your own device
  • Hddiag.exe - Double-click this file and choose "Run" if ask to have access to your device, say "Yes" and the Troubleshooting Options windows appears.

[Help Desk Diagnostic Utility - Troubleshooting Options window]

2. Click each area in the first column, i.e. click "Flush DNS Cache", then click "Reset DNS Servers", etc.

3. Click each area in the second column, i.e. click "Disable NetBIOS over TCP/IP" and then click "Enable DHCP"

4. Click from the third column "Generate Text Report" and this file will be placed on your desktop named "helpdesk.txt"

5. Attach this report (which is an IPConfig file) to your request. (This report will be read by the Help Desk and our Network Technicians) The results will help our network team isolate the network issue. You can run it when it's working and run it again when you are experiencing the issue. This can be done on both WiFi and Ethernet.

6. After we read the results we will recommend the next step. 

Mac

When the network connection is working as expected

1. Use Spotlight search (Command+Space Bar) to search for 'Terminal App', hit enter when found. This will launch Terminal window.

[Terminal screen on Mac]

2. Copy the following commands (one at a time) below and paste them into the Terminal window.

AIRPORT=/System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport
LOGFILE=$HOME/Desktop/WiFi.good.`date "+%y%m%d%H%M%Z"`.txt
echo NOT working >>$LOGFILE
date >>$LOGFILE
uname -a >>$LOGFILE
$AIRPORT prefs >>$LOGFILE
$AIRPORT -I >>$LOGFILE
$AIRPORT -s >>$LOGFILE
netstat -rln >>$LOGFILE
netstat -bi >>$LOGFILE
ifconfig >>$LOGFILE
scselect >>$LOGFILE
arp -a >>$LOGFILE
nslookup mit.edu >>$LOGFILE
dig rpi.edu >>$LOGFILE
ping -c 10 rpi.edu >>$LOGFILE

3. Verified that you can see the last line of 'ping' command on it. It might take a few second

[PING command screen]

4. A text file with the name 'WiFi.good.YYMMDDHHMM.txt' should be generate on your desktop. You can see the example here. 

When the network connection is NOT working as expected

1. Please follow the steps above to launch 'Terminal'. Copy and paste the following commands (one at a time) below and paste them into the Terminal window. 

AIRPORT=/System/Library/PrivateFrameworks/Apple80211.framework/Resources/airport
LOGFILE=$HOME/Desktop/WiFi.bad.`date "+%y%m%d%H%M%Z"`.txt
echo NOT working >>$LOGFILE
date >>$LOGFILE
uname -a >>$LOGFILE
$AIRPORT prefs >>$LOGFILE
$AIRPORT -I >>$LOGFILE
$AIRPORT -s >>$LOGFILE
netstat -rln >>$LOGFILE
netstat -bi >>$LOGFILE
ifconfig >>$LOGFILE
scselect >>$LOGFILE
arp -a >>$LOGFILE
nslookup mit.edu >>$LOGFILE
dig rpi.edu >>$LOGFILE
ping -c 10 rpi.edu >>$LOGFILE

2. A text file with the name 'WiFi.bad.YYMMDDHHMM.txt' should be generate on your desktop. You can see the example here

3. Submit an online Support Request and make sure to attach the diagnostics txt file(s). 

Last Reviewed: 23-Sep-2021