1. What Is Happening?
When you type a website address like pittmail.pitt.edu into your browser, your computer first has to look up the address behind that name — similar to looking up a phone number before you can make a call. This lookup is called a DNS query, and it happens automatically in the background every time you open a website or application.
When this lookup fails, you will usually see an error message in your browser such as:
| Error Message You Might See |
What It Means in Plain English |
| "This site can't be reached" |
Your computer could not find the address for that website name. |
| "DNS address could not be found" |
The address lookup failed — the phone book couldn't find the number. |
| "Server not found" |
Your computer found the address lookup service but got no answer for that site. |
| "ERR_NAME_NOT_RESOLVED" |
The website name could not be translated to an address your computer can use. |
| "Hmm. We're having trouble finding that site." |
Your browser cannot look up the address — usually a DNS or network issue. |
| 💡 GOOD TO KNOW: A DNS problem is not the same as a network outage. Your Wi-Fi or ethernet connection can be working perfectly while DNS is failing. If you see a DNS-related error, your internet connection is probably fine — your computer just cannot translate website names into addresses right now. |
2. Before You Start — Two Quick Checks
Check A — Is There a Known Outage?
Before troubleshooting your own device, check whether the issue is already known and being worked on. Visit the Pitt IT status page at status.pitt.edu. If a DNS or network incident is already posted there, you do not need to troubleshoot — wait for the issue to be resolved and check back for updates.
Check B — Are You Working Off-Campus?
Many Pitt websites and applications are only accessible from within the Pitt network. If you are working from home, a coffee shop, or anywhere outside of campus, you must be connected to PittNet VPN (GlobalProtect) to reach most internal Pitt resources.
| Your Situation |
What to Do |
| Working off-campus and VPN is not connected |
Connect to GlobalProtect VPN first, then try again. VPN instructions: technology.pitt.edu |
| Working off-campus and VPN is connected |
Try disconnecting VPN, wait 30 seconds, reconnect, then try again. If still failing, continue to Section 3. |
| Working on campus (in a Pitt building) |
VPN is not required on campus. Continue to Section 3. |
3. Try These Steps First
Work through these steps in order. After each step, try opening the website or application again before moving to the next step.
Step 1 — Reload the Page
Press F5 (Windows) or Command + R (Mac) to reload the page. Occasionally a one-time lookup failure resolves itself on the next attempt. If you get the same error, continue to Step 2.
Step 2 — Try a Different Browser or Device
Open a different web browser (e.g., if you use Chrome, try Edge or Firefox) and try the same address. Also try from your phone or another computer if one is available.
| Result |
What This Tells You |
| Works in the other browser or on another device |
The problem is specific to your browser or original device. Try clearing your browser cache (Section 4) or contact the Help Desk. |
| Fails on all browsers and devices in the same location |
The problem is likely with the network you are on or with the site itself. Continue to Step 3. |
| Works on your phone (mobile data, not Wi-Fi) but not on your computer |
The problem is specific to your computer or the Wi-Fi network you are on. Continue to Step 3. |
Step 3 — Restart Your Computer
A full restart (not just closing the lid) clears your computer's local DNS cache and refreshes its network settings. Save your work, restart completely, and try again. This resolves a large number of DNS-related issues on its own.
Step 4 — Check That Other Websites Work
Try opening a few different websites to understand the scope of the problem:
| Try Opening |
Result |
What This Tells You |
| www.google.com (a public site) |
Fails |
Your device cannot reach any website — likely a broader network or DNS issue. Contact the Help Desk. |
| www.google.com (a public site) |
Works |
Your internet connection and basic DNS are working. The problem is specific to the Pitt resource or application you were trying to reach. Continue to Step 5. |
| my.pitt.edu (a Pitt internal site) |
Fails while google.com works |
The issue is specific to Pitt internal resources. If off-campus, ensure VPN is connected. If on campus, contact the Help Desk. |
Step 5 — Check That You Have the Right Address
Confirm that the web address you are using is correct. A small typo in a website address — a missing letter, an extra period, or a wrong word — will cause a "site not found" error that looks identical to a DNS failure but is simply a misspelling. Double-check the address against the official Pitt IT website at technology.pitt.edu or ask a colleague for the correct link.
4. Clear Your Browser's Cache
Your browser stores a temporary copy of website addresses it has looked up before. If that stored copy is outdated — for example, a Pitt system moved to a new address — your browser may keep trying the old one. Clearing the cache forces your browser to look everything up fresh.
| Browser |
How to Clear Cache |
| Chrome |
Press Ctrl + Shift + Delete (Windows) or Command + Shift + Delete (Mac). Select "Cached images and files" and "Cookies and other site data." Set the time range to "All time" and click Clear data. |
| Edge |
Press Ctrl + Shift + Delete. Check "Cached images and files." Set the time range to "All time" and click Clear now. |
| Firefox |
Press Ctrl + Shift + Delete (Windows) or Command + Shift + Delete (Mac). Select "Cache" and set the time range to "Everything." Click Clear Now. |
| Safari (Mac) |
From the menu bar, click Safari > Clear History. Choose "all history" and click Clear History. |
After clearing the cache, close and reopen your browser, then try the website again.
5. Clear Your Computer's DNS Cache
Separate from the browser cache, your operating system also keeps its own list of recently looked-up website addresses. Clearing this forces your computer to look up addresses completely fresh from the network. This is often the fix when a site was moved or updated and your computer is still remembering the old address.
On Windows
- Click the Start button and type cmd in the search box.
- Right-click Command Prompt and select Run as administrator.
- In the black window that opens, type the following and press Enter:
ipconfig /flushdns
- You should see the message: "Successfully flushed the DNS Resolver Cache."
- Close the window and try your website again.
On Mac
- Click the Finder icon in your Dock, then open Applications > Utilities > Terminal.
- In the Terminal window, type the following and press Return:
sudo dscacheutil -flushcache && sudo killall -HUP mDNSResponder
- You will be prompted for your Mac password. Type it and press Return. (You will not see the password as you type — this is normal.)
- No confirmation message will appear, but the cache has been cleared.
- Close Terminal and try your website again.
| 💡 TIP: If you are not comfortable running commands, a full computer restart will also clear the DNS cache automatically. This is always a safe alternative to the steps above. |
6. Check Your Network Connection
Sometimes what looks like a DNS problem is actually a network connection issue. Try the following:
- If using Wi-Fi: Turn Wi-Fi off on your device, wait 10 seconds, then turn it back on. Alternatively, try connecting to a different Wi-Fi network if one is available.
- If using a wired connection: Unplug the network cable from your computer, wait 10 seconds, and plug it back in.
- Restart your router or modem (off-campus only): Unplug the power, wait 30 seconds, and plug it back in. Wait 2 minutes for it to fully restart before testing.
- Try Ethernet instead of Wi-Fi (or vice versa): If you can switch between a wired and wireless connection, try the other one.
If none of the above helps and you are on campus, the issue may be with the building's network connection. Contact the Help Desk and mention which building and room you are in.
7. Specific Situations
I Can Only Access the Site by Typing Its Address Differently
If adding or removing www. from the address makes the difference, or if one version works and the other does not, this is a DNS record issue — not something you can fix yourself. Note the exact address that fails and contact the Help Desk.
The Site Started Failing After I Changed Something
If the problem started after installing new software, changing network settings, or switching to a new device, mention this to the Help Desk — it helps pinpoint the cause quickly.
I'm Being Redirected to a Strange or Unfamiliar Page
If instead of an error you are being sent to an unexpected page — especially one asking for a login or showing advertisements — do not enter any information. This may indicate a security issue.
| ⚠️ SECURITY ALERT: If you are being redirected to unexpected pages, your device may have been compromised. Do not enter passwords or personal information. Disconnect from the network and contact the Pitt IT Security Operations team immediately at x4357 or security@pitt.edu. |
I Just Deployed or Set Up a New System and It Can't Be Reached by Name
New servers and applications need their names registered in Pitt's DNS system before others can find them by name. This does not happen automatically for all resource types. Contact the Help Desk and ask them to open a request with Network Engineering to register the new hostname.
Everyone Around Me Is Having the Same Problem
If multiple people in the same room or building are all experiencing the same DNS or connectivity issue at the same time, skip the personal troubleshooting steps and call the Help Desk or NOC directly. This is a sign of a broader infrastructure issue that individual users cannot fix.
8. When to Contact the Help Desk
Stop troubleshooting on your own and contact the Help Desk if any of the following are true:
| Contact the Help Desk if... |
| You have tried all the steps above and the problem persists |
| Multiple people around you are experiencing the same problem |
| A critical application (email, HR system, student portal) is completely unreachable |
| You are being redirected to unexpected or suspicious pages |
| The problem started after a Pitt system or network change that you did not make |
| You need a new hostname or application registered in Pitt DNS |
| You are not comfortable performing any of the steps in this article |
What to Tell the Help Desk
The more information you provide, the faster the Help Desk can identify and fix the problem. Try to have the following ready:
- The exact website address or application name that is not working
- The exact error message you see on screen (a screenshot is ideal)
- When the problem started
- Whether you are on campus or off-campus, and if off-campus whether VPN is connected
- Whether others near you are experiencing the same issue
- Which steps from this article you have already tried
- Whether the site works on a different device or browser
Help Desk Contact Information
| Contact Method |
Details |
Best For |
| Phone |
412-624-HELP (4357) |
Urgent issues affecting your ability to work or study right now |
| Online Ticket (TDX) |
Submit a Ticket |
Non-urgent issues; allows you to attach a screenshot of the error |
| Walk-In |
The Technology Help Desk, 1st floor Hillman Library |
In-person assistance with your device |
| IT Status Page |
status.pitt.edu |
Check for known outages before contacting the Help Desk |
9. Revision History
| Version |
Date |
Author |
Changes |
| 1.0 |
2026-02-25 |
Network Operations Team |
Initial release — end-user DNS troubleshooting guide in plain language |
University of Pittsburgh — Information Technology Services — Help Desk Knowledge Base | PITT-KB-DNS-004