Your dns server might be unavailable là lỗi gì năm 2024

Khi gặp phải lỗi này bạn sẽ không thể truy cập được internet, gây nên một số trở ngại không hài lòng cho người dùng. Màn hình máy tính sẽ xuất hiện dòng chữ "Your computer appears to be correctly configured, but the device or resource (DNS server) is not responding" khi gặp phải lỗi này.

Màn hình máy tính báo lỗi

Một số lý do gây ra lỗi về kết nối này có thể là do:

- Lỗi từ card mạng hoặc Router

- Gián đoạn dịch vụ DNS trên máy tính

- Do chương trình diệt virus hoặc Firewall (tường lửa) chặn truy cập kết nối Internetdẫn tới lỗi kết nối máy chủ Cloud.

2. Cách khắc phục lỗi DNS server isn't responding

Để khắc phục lỗi DNS server isn't responding bạn có thể tham khảo theo trình tự sau đây.

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Bước 1: Đầu tiên, bạn chọn Start sau đó click vào Run > Run

Bước 2: Trên cửa sổ lệnh Run, bạn tìm kiếm Network and Sharing > Network and Sharing

Bước 3: Trên của sổ Network and Sharing, click Change adapter settings

Bước 4: Kích chuột phải chọn Properties

Bước 5: Trên cửa sổ Local Area Connection Properties bạn click chọn tùy chọn Internet Protocol Version 4 (TCP/IPv4) để tiến hành thay đổi DNS server mặc định thành DNS Google hoặc OpenDNS.

Xem thêm:Điện toán đám mây

Trên cửa sổ Internet Protocol Version 4 (TCP/IPv4) bạn click chọn tùy chọn Use the following DNS server address và nhập địa chỉ DNS của Google:

- Preferred DNS Server là: 8.8.8.8

- Alternate DNS Server là: 8.8.4.4

Nếu muốn sử dụng OpenDNS, bạn sử dụng địa chỉ:

- Preferred DNS Server là: 208.67.222.222

- Alternate DNS Server là: 208.67.220.220

Đánh tích chọn mục Validate settings upon exit rồi click chọn OK.

Bước 6: Mở lại Run, sau tìm kiếm cmd.exe vào cửa sổ lệnh Run rồi ấn Enter

Tiếp theo, bạn nhập lệnh ipconfig /all trên Command Prompt rồi nhấn Enter.

Tìm và note lại địa chỉ Physical Address.

Bước 7: Mở lại Network and Sharing Center. Tại đây tìm và kích chuột phải vào mạng bạn đang kết nối rồi click chọn Properties.

Tiếp theo click chọn Configure và chọn thẻ Advanced. Trên thẻ Advanced, bạn tìm Network Address và điền địa chỉ Physical Address mà bạn vừa note lại ở bước trên.

Today’s internet is more resilient than it was even five years ago. There’s more redundancy, and resources are more distributed. We’ve grown accustomed to having access without interruption. That’s why messages such as “DNS server not responding”, “DNS Server Unavailable” or “Server DNS Address could not be found” can bring on panic attacks. To help calm the nerves, here are some tips for resolving DNS issues.

“Is anyone else’s internet not working?” is the modern office’s equivalent to pulling the fire alarm in a high school—the quickest way to cause hell to break loose. Around half of the time, it’s just the one person who cries wolf that’s having issues—typically solvable with some browser troubleshooting techniques. However, if you run a network diagnostic and are greeted by this message: “Your DNS server might be unavailable,” additional troubleshooting may be in order.

There are a few possible reasons as to why your DNS server might be unavailable. It could be that your browser’s cache needs to be refreshed, or perhaps your router is malfunctioning. The DNS server you are using could be acting up or maybe your firewall is causing problems. All of these issues can lead to that same annoying error message, which means there are also a list of different solutions. But don’t worry, we’re here to talk you down from the ledge and walk you through some DNS troubleshooting.

How Do DNS Servers Work?

When you have DNS problems, understanding how DNS servers work can help with troubleshooting. A website has a name and a number. The name is what users key in a browser, such as https://electric.ai, to access a site. Tied to that domain name are numbers or IP addresses that tell the internet the website’s location. That is the task of a DNS server –to tie the name to the number.

When a website’s name is entered, the browser asks the nearest DNS server for its IP address. The DNS server returns the IP address, and the browser connects to the webpage that then appears on your screen. End users are unaware of the background tasks required to make the system work.

If the DNS server is unavailable, the browser has no way of acquiring the website’s IP address, so it returns an error. Now everyone knows the server is down because it only takes seconds for the news to spread.

How To Fix DNS Server Unavailable

DNS-related problems can be caused by any of the following:

• Browser
• Computer
• Router
• ISP

If the issue is browser or router related, you may be able to correct the problem without outside assistance. If the problem resides with your ISP or DNS server, it’s going to take a little more time to resolve.

Browser

Sometimes the problem isn’t the DNS server; it’s the browser. If it is, one of the following tips should fix the problem:

• Reset the Browser. The first step is to close or quit the browser and restart. Sometimes, it is that simple.
• Clear the Browser’s Cache. For frequently-accessed websites, webpages are cached (stored) on a local computer for faster load times. Cached website and IP addresses do not always update. If the computer is trying to access a website using an outdated IP address, the request will fail. Clearing the browser’s cache should fix the problem.
• Use a Different Browser. The final test is to try a different browser. If using Firefox, try using Chrome or Safari to access the web. If using a different browser fixes the problem, you may need to update the default browser. If updates do not work, consider uninstalling and reinstalling the software to see if it fixes the problem.

If the DNS is still unavailable after trying these tips, it’s time to check routers and computer settings.

Computers

When a computer or router is first used, DNS settings are entered into the device to ensure they can connect to the appropriate DNS server. Sometimes those settings change, so it’s an excellent idea to check the device settings when a DNS problem occurs.

• Check DNS Settings. Ask the network administrator or ISP for the correct DNS settings. Then, check the DNS settings on the computer to confirm they are correct. If using services such as OpenDNS, be sure to check with the network or ISP for incompatibility issues.
• Deactivate Firewall or Antivirus Programs. Firewalls and antivirus software can block IP addresses or websites. The easiest way to check is to deactivate the programs and try to connect to the internet. If successful, recheck the DNS configurations in the firewall and antivirus programs.
• Disable Secondary Connections. If the computer has other open connections such as Bluetooth, disable all other connections to avoid conflicts. On a Windows system, disable the peer-to-peer feature.
• Update Network Adapter Drivers. Check that network adapters are up-to-date. If not, update drivers and try connecting again.

From Ken Lewellen, Level II Technician at Electric:

Another thing you might consider is flushing the DNS resolver cache from the local machine/device. It varies from OS but here is a link with descriptions. You can read more details here: https://tinyurl.com/2kzp3fvs

Check for static DNS addresses on the computer. Some users tend to use Google’s DNS 8.8.8.8 or 8.8.4.4. Setting it to automatic will request the DNS server from the router/ISP.

If the DNS settings are correct on devices, but the DNS server is still unavailable, it’s time to check the router.

Routers

Routers can cause problems connecting to DNS servers. The settings might be incorrect, or the router itself may need to be replaced. Here are tips for troubleshooting routers.

• Connect to the Ethernet. To determine if a router is the problem, switch to a cabled connection. Connect a computer to the router using an ethernet cable. If using the ethernet connection solves the problem, the router is probably at fault. Confirm that the router is configured correctly.
• Restart the Router. Resetting a router may help resolve a DNS issue. When a router is reset, its cache will be refreshed, which may resolve the issue. Unplug the router and modem. Wait at least 15 seconds before plugging the power cables back in. Wait for the devices to come online.
• Update Router. Check for router updates. If available, consider applying the updates.
• Reset you Router to Default Settings. It’s not uncommon to see custom DNS settings applied to home routers. This is usually used to bypass an ISP’s DNS server and provide an alternative to manually setting each devices DNS. If unsure, resetting the router to default is an option to clear out any custom settings.

If routers are working, the problem probably resides with an ISP.

ISP

ISPs maintain DNS servers. On occasion, something changes at the service that requires a local change. If that happens, the internet connection may fail.

• Is it the ISP? An ISP’s DNS server may be down. To check, ping the IP addresses of the DNS servers. Remove any addresses that do not respond. To find the IP addresses, select the “Obtain DNS server address automatically.” If the option is not available, contact the ISP.
• Is it the DNS Server? If a DNS server becomes overwhelmed or malfunctions, it will become unavailable. Using the list of DNS server addresses, try switching to another DNS server.
• Could it be Your Company’s Sever? Not necessarily ISP related, but if a user is connecting to a VPN, or is on a local work network, they may be getting a DNS address from their company’s server. If that’s the case and they’re getting DNS errors, the server may need to be looked at.

Interested in learning more about how Electric can help ensure your company’s running as efficiently as possible? Attend our next Innovation Series webinar to see how Electric can improve your IT!

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How to Avoid DNS Issues

We can’t eliminate all DNS issues, but we can reduce the possibilities of problems. Resetting or clearing the DNS cache can also help if the user travels a lot, or connects to many different networks. At Electric, we work to proactively identify and troubleshoot potential concerns such as:

• Ensure software, drivers, and devices are up to date.
• Monitor infrastructure health and security.
• Use network diagnostics for such things as speed tests.

If a problem does occur, we have a three-step process that we follow once you have contacted us.

Step 1. Our IT experts will investigate the issue using mobile device management (MDM) software so they can see what you see.

Step 2. Our team systematically explores potential problem areas such as browser updates or router settings to minimize the time required to resolve the issue.

Step 3. We will work with the ISP, DNS service, or hardware manufacturers until the DNS server is working.

Your company doesn’t have to sit by the phone or monitor activity as third-parties attempt to resolve the problem. You can get back to focusing on what you do best while we focus on what we do best.