Incorrect DNS configuration, slow web page opening, video loading circle?

I think that the broadband at home is 100 gigabits or more than gigabit, but the network speed is very stuck, is it because the operator has not given enough? In fact, this may be because your DNS is not configured with pairs.
DNS the configuration is correct, and when you open the web page, it is visible to the naked eye that it is faster.

DNS is the first threshold of the network, which is not only faster to open web pages, but also anti-hijacking, anti-pollution, and advertising filtering. This article explains how to match it clearly.

Problem Diagnosis: How will the network speed be affected if the DNS configuration is incorrect?

first confirm what kind of situation you are experiencing

Common Causes (sorted by frequency):

• routers default DNS to carrier-assigned – slow and sneaky hijacking
• DNS The server address is filled in incorrectly - it fails to parse any number missing
• devices are equipped with different DNS - mobile phones are fast and computers are slow, and I don't know which one to change
• IPv6 DNS is not synchronized with the configuration - IPv6 takes precedence and takes a slow line
• cache pollution - The router's DNS cache has been cached for too long, and the domain name IP has changed but is not updated

Solution

Option 1: Modify the router's DNS (the most thorough, one change will take effect for the whole house)

the right way to change your DNS:

the carrier's default DNS → is replaced with public DNS, one-size-fits-all on the router, and all devices automatically take effect.

Recommended Public DNS at a glance:

preferred for domestic users: 223.5.5.5 + 223.6.6.6 (Alibaba) , and 8.8.8.8 for overseas needs as an alternative.

Modification Steps (General Router):

Enter the router address
1. the browser to log in (192.168.1.1 / 192.168.0.1 / 192.168.31.1)
2. find "Network Settings"→ "WAN Port Settings" or "Internet Settings"
3. find "Manually assign DNS" or "Advanced DNS"
4. populate the primary DNS:223.5.5.5
5. Fill in the alternate DNS:223.6.6.6
6. save, restart your router

TP-Link Setup Path:
Network Parameters → WAN Port Settings → Advanced → Find DNS Server Fill in the

Xiaomi router setup path:
common settings → WiFi settings → WiFi advanced settings → custom DNS

Huawei router:
more features → Network settings → WAN port settings → DNS settings

💡

tips : If the router does not have a separate DNS setting item, look for it in the advanced settings of PPPoE dialing on the WAN port, which is usually mixed up.

Pits:

❌
• Don't fill in 114.114.114.114 (hijacked by exposure, not recommended)
❌
• Don't fill in the DNS of two different carriers at the same time - it will slow down if they don't support each other
❌
• Don't just fill in one DNS - the main DNS is hung and the website cannot be opened, and the backup DNS is to save your life

Scenario 2: Configure IPv6 DNS (IPv6 Off-Road) at the same time

IPv6, many devices will give priority to IPv6 DNS, and if only IPv4 DNS is configured, IPv6 may go on the operator's slow line.

know if they have IPv6?

• Open test.ipv6.test.ustc.edu.cn
• can open → has IPv6

IPv6 DNS Recommendation:

Modification Steps:

1. Log in to the router background
2. find the "IPv6" setting (which may be in "Advanced Settings" or "Network Parameters"
3. "IPv6 DNS" manually populated:
   • Owner: 2400:3200::1
   • :2400:3200:baba::1
4. save, restart

Scenario 3: Clear your router's DNS cache

after changing the DNS, some domain names are still resolving to the old IP (cached).

Clearing Method:

Method A: Restart your router

• the easiest, empty all cache after restarting
• wait 2-3 minutes for full start

Method B: Command Line Purge (Power Users)

log in to the router background → find "System Tools" → "Restart"

or SSH (supported by some routers):

# Log in to the router background (telnet or SSH) # Different router commands are slightly different killall -SIGHUP dnsmasq # Clear DNS cache 

or restart your DNS service directly:

/etc/init.d/dnsmasq restart 

Scenario 4: Assign a specific device to a specific DNS

router has changed its DNS, but some devices (such as smart TVs, game consoles) use their own DNS and are not affected.

TV/Box DNS Optimization (De-Ads + Acceleration):

1. open the TV settings → network → WiFi details
2. DNS1: 223.5.5.5 (Alibaba)
3. DNS2: 119.29.29.29 (Tencent)
4. confirm the saving

computer (Windows):

1. Right-click "Network"→ "Properties"→ "Change Adapter Settings"
2. double-click on the network you're using →Properties"
3. double-click Internet Protocol Version 4 (TCP/IPv4)
4. select "Use DNS server address below"
5. Fill in 223.5.5.5 / 223.6.6.6
6. do the same for IPv6, populate 2400:3200::1 / 2400:3200:baba::1

Mac Individually specified:

System Preferences → Network → Wi-Fi → Advanced → DNS → Add 223.5.5.5 / 223.6.6.6

Scenario 5: Encrypt DNS requests with DNS-over-HTTPS (DoH)

advanced gameplay: DNS requests themselves can also be monitored/hijacked by operators, and cannot be recognized or hijacked by operators after DoH encryption.

DoH-enabled router (firmware support required):

• Xiaomi/Redmi router (some models need to flash the development version firmware)
• OpenWrt / Merakin / Pandorabox and other third-party firmware
• ASUS router (native DoH support)

setup method (ASUS as an example):

1. Log in to the background of your ASUS router
2. external network → internet connection → DNS settings
3. enable Resolve via DoH or Resolve DNS via TLS
4. DoH URL population:
   • Cloudflare：https://cloudflare-dns.com/dns-query
   • Google：https://dns.google/dns-query
5. save

pit avoidance:

❌
• DoH will slightly increase latency (about 5-10ms), but it's worth it for privacy
❌
• Some schools/enterprises prohibit DoH on their networks, and you will not be able to access the Internet if you turn on DoH
❌
• Xiaomi router unofficial firmware Do not turn on DoH, it may be unstable

DNS Optimization effect measurement

compare DNS resolution speeds before and after optimization by:

method: Test DNS response time with nslookup

open the command line (Windows press Win+R to type cmd, Mac to open Terminal):

nslookup www.baidu.com 223.5.5.5 

look at the last line "Response time", the normal value:

• < 10ms: DNS servers are in the country and extremely fast ✅
• 10-50ms: Normal level
• > 100ms :D NS is problematic, it may be a cross-provincial resolution

final reminder

Changing DNS on
• router is the most valuable operation , and once the change takes effect, all devices will benefit
• domestic preferred 223.5.5.5 + 223.6.6.6, stable, fast, less hijacking
• IPv6 DNS don't miss , or IPv6-first devices will go ahead
• TV and box are equipped with separate DNS, many video apps are slow to resolve DNS issues
• regularly test the DNS speed , and replace the carrier's DNS in time if it is unreliable

DNS The configuration is wrong, and all other optimizations are in vain. Get the DNS done first, and then test the network speed to be real.

use? Which one is the DNS with now? Talk about it in the comment area and help you see if the configuration is correct.