Incorrect DNS configuration, slow webpage loading, video loading and spinning?

my home broadband is 100 Mbps or above gigabit, but the speed is very slow. Is it because the carrier hasn't provided enough? Actually, this might be because your DNS settings are not configured correctly.
DNS the specs were correct, and when you open the webpage, you can visibly see the speed up.

DNS is the first barrier to the internet. With proper configuration, web pages not only open faster, but also prevent hijacking, pollution, and ad filtering. This article clearly explains how to match them.

Diagnosis: What impact can incorrect DNS configuration affect network speed?

first confirm which situation you are facing:

Common Causes (sorted by frequency):

• router's default DNS is assigned by the carrier slow and secretly hijacking
• DNS Server address is entered incorrectly — missing one digit fails parsing
• each device is equipped with different DNS — the phone is faster, the computer is slower, and I don't know which to change
• IPv6 DNS not synchronized — IPv6 prioritized by taking a slow line
• cache pollution — router DNS cache for too long, domain IP changes but hasn't been updated

Solution

Option 1: Change the router's DNS (most thoroughly, the change takes effect throughout the entire house)

the correct approach to changing DNS:

carriers change the default DNS → to public DNS, on routers in one go, all devices automatically take effect.

Recommended Public DNS Overview:

Domestic users' preferred choice: 223.5.5.5 + 223.6.6.6 (Alibaba) , with overseas demand additionally adding 8.8.8.8 as backup.

Modification Steps (Universal Router):

1. browser enters the router address 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 either "Manual DNS Specification" or "Advanced DNS"
4. enter the main DNS:223.5.5.5
5. Enter backup DNS:223.6.6.6
6. save, restart the router

TP-Link Setting Path:
Network Parameters → WAN Port Settings → Advanced → Find DNS Server and Enter

Xiaomi router setup path:
Common Settings → WiFi Settings → WiFi Advanced Settings → Custom DNS

Huawei router settings path:
more features → network settings → WAN port settings → DNS settings

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tip : If the router does not have a separate DNS setting option, look for it in the advanced settings for WAN port PPPoE dial-up, which is usually mixed together.

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pitfalls to avoid:

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• Do not fill in 114.114.114.114 (already exposed and hijacked, not recommended)
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• Do not enter DNS from two different carriers at the same time—if they don't support each other, speed drops
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• Don't just enter one DNS—if the main DNS is down, the website won't be opened; backup DNS is just for survival

Solution 2: Configure IPv6 DNS simultaneously (to prevent IPv6 from taking a wrong path)

After

IPv6 becomes widespread, many devices will prioritize IPv6 DNS. If only IPv4 DNS is installed, IPv6 may use carrier slow lines.

How can you check if you have IPv6?

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

IPv6 DNS recommendation:

Modification Steps:

1. Log in to the router's backend
2. find the "IPv6" setting option (which may be in "Advanced Settings" or "Network Parameters")
3. Manually enter the "IPv6 DNS":
   • Host: 2400:3200::1
   • Availability: 2400:3200:baba::1
4. save, restart

Solution 3: Clear the router's DNS cache

after changing the DNS, some domain names still resolve old IPs (cached).

removal method:

Method A: Restart the router

• is the simplest: after rebooting, all caches are cleared
• wait 2-3 minutes for it to fully start

Method B: Command Line Clearing (Advanced User)

Log in to the router's backend → find 'System Tools' → 'Restart'

or SSH (supported by some routers):

# Log in to the router's backend (telnet or SSH)
# Commands vary slightly depending on the router
killall -SIGHUP dnsmasq # Clear DNS cache

or directly restart DNS services:

/etc/init.d/dnsmasq restart

Option 4: Assign a specific DNS

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

TV/Box DNS Optimization (Ad Removal + Acceleration):

1. Open TV Settings → Network → WiFi Details
2. DNS1: 223.5.5.5 (Alibaba)
3. DNS2: 119.29.29.29 (Tencent)
4. confirm and save

Computer Specified Separately (Windows):

1. Right-click "Network"→ "Properties"→ "Change adapter settings"
2. double-click the network you are using → "Properties"
3. Double-click "Internet Protocol Version 4 (TCP/IPv4)"
4. select "Use the following DNS server addresses"
5. fill in 223.5.5.5 / 223.6.6.6
6. the same operation for IPv6, enter 2400:3200::1 / 2400:3200:baba::1

Mac Individual Designation:

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

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

advanced gameplay: DNS requests themselves can be monitored or hijacked by ISPs; after DoH encryption, ISPs cannot recognize or hijack them.

DoH-supported router (firmware required):

• Xiaomi/Redmi router (some models require flashing developer firmware)
• OpenWrt / Merakin / Pandorabox and other third-party firmware
• ASUS router (natively supports DoH)

setup method (using ASUS as an example):

1. Log in to the ASUS router backend
2. External network → Internet connection → DNS settings
3. enable "DNS resolution via DoH" or "DNS resolution via TLS"
4. DoH URL Entry:
   • Cloudflare：https://cloudflare-dns.com/dns-query
   • Google：https://dns.google/dns-query
5. Preserve

pitfalls to avoid:

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• DoH slightly increases latency (about 5-10ms), but the privacy protection is worth it
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• Some schools/enterprises prohibit DoH networks, making it impossible to access the internet during DoH meetings
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• Do not enable DoH on unofficial Xiaomi routers, as it may be unstable

DNS Optimization Effect Test

compare DNS resolution speeds before and after optimization using the following methods

method: Test DNS response time with nslookup

Open the command line (press Win+R on Windows and type cmd; Mac opens Terminal):

nslookup www.baidu.com 223.5.5.5

check the last line "Response time"; normal value:

• < 10ms: DNS servers in China are extremely fast ✅.
• 10-50ms: Normal level
• > 100ms :D NS has issues, possibly cross-province resolution

Final reminder

Changing DNS on
• router is the most worthwhile ; once the change takes effect throughout the entire house, all devices benefit
• the domestic top choice 223.5.5.5+ 223.6.6.6, stable, fast, and low hijacking
• IPv6 DNS must not be overlooked, or IPv6-preferred devices will take a detour
• TV and box are paired separately DNS, many video apps have slow resolution due to DNS issues
• regularly test DNS speed and replace carrier DNS promptly if unreliable

DNS If the configuration is wrong, all other optimizations are useless. First, get the DNS right, then test the speed—that's the real deal.

using? Which DNS is configured with now? Share your thoughts in the comments and help you see if the configuration is correct.