DNS Issue Resolution

Issue

DNS server not responding
DNS_PROBE_FINISHED_NXDOMAIN
ERR_NAME_NOT_RESOLVED
Server DNS address could not be found
Timeouts and failed updates
unable to reach Duquesne sites/pages

Environment

• Windows 10/11
• macOS (Ventura and later)
• iOS (16 and later)
• Android (12 and later)

Cause

The device is configured with a hardcoded (static) DNS server instead of using the DNS servers assigned automatically by the campus network. This can interfere with proper name resolution, prevent access to internal resources, cause delays in reaching websites, or bypass important security and routing policies. Hardcoded DNS settings may also persist across networks, leading to unexpected behavior when switching between on-campus and off-campus environments.

Resolution

Check Your DNS

Windows 10/11

1. Go to Control Panel > Network and Internet > Network and Sharing Center
2. Click Change adapter settings
3. Right-click your active connection and select Status
4. Click the Details... button
5. Look for the line labeled IPv4 DNS Server — this shows your current DNS servers

macOS (Ventura and later)

1. Go to the Apple menu > System Settings > Network
2. Select your active connection (e.g., Wi-Fi or Ethernet)
3. Click the details next to it
4. Scroll to the DNS section on the left — your current DNS servers will be listed there

iOS (16 and later)

1. Go to Settings > Wi-Fi
2. Tap the “i” icon next to your connected network
3. Scroll to the DNS section — it will show either Automatic or list specific DNS servers

Android (12 and later)

Note: Steps may vary depending on device and manufacturer

1. Go to Settings > Network & Internet > Internet
2. Tap your connected Wi-Fi network
3. Tap the gear icon > Advanced settings
4. Look under IP settings or Private DNS
   • If set to DHCP, DNS is assigned automatically
   • If set to Static or Private DNS, the DNS servers will be listed

Command Line Options

Windows 10/11

Check DNS Configuration:
ipconfig /all
Look for the "DNS Servers" entry under your active adapter.

Flush DNS Cache:
ipconfig /flushdns
This clears the DNS resolver cache. You should see: "Successfully flushed the DNS Resolver Cache."

macOS (Ventura and later)

Check DNS Servers:
scutil --dns
Look under "resolver #" sections for "nameserver."

Flush DNS Cache:
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
No confirmation message is returned. You can test name resolution again afterward.