What factors affect DNS propagation time, and what is DNS propegation

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When you update the DNS (Domain Name System) for your domain name (This can be from updating name servers, or renewing an expired domain name, or registering a new domain name) , it can take up to 48 hours for those changes to propagate throughout the Internet.

While we strive to make updates as quickly as possible, the DNS propagation time for your domain name depends on several factors that we cannot control.

NOTE: Many of the updates you can make in the cPanel affect the DNS records in your domain name's zone file. For example, if you add a new sub-domain, change a MX record, add a parked / addon domain, you update your domain name's zone file.

Factors that affect DNS propagation time include:

  • Your TTL (Time to Live) settings — On premium hosting you can set the TTL for each DNS record in your domain name’s zone file using the advanced dns zone editor. TTL is the time period for which servers cache the information for your DNS records. For example, if you set the TTL for a particular record to one hour, servers store the information for that record locally for an hour before retrieving updated information from your authoritative nameserver. Shorter TTL settings make can increase propagation speed. However, shorter settings also increase the number of queries to your authoritative nameserver, and that increased load slows your server’s processing time.
  • Your ISP (Internet Service Provider) — Your ISP caches DNS records (stores the data locally rather than retrieving fresh data from your DNS server) to speed up Web browsing and reduce traffic, which slows your propagation time. Some ISPs ignore TTL settings and only update their cached records every two to three days.
  • Your domain name’s registry — If you change your domain name’s nameservers, we relay your change request to the registry within minutes, and they publish your authoritative NS (nameserver) records to their root zone. Most registries update their zones promptly. For example, VeriSign refreshes zones for .com domain names every three minutes. However, not all registries make updates that quickly. Registries often protect their root nameservers from overuse by setting a high TTL of up to 48 hours or more for those NS records. In addition, even though recursive nameservers should not cache the root NS records, some ISPs cache the information anyway, which can result in a longer nameserver propagation time.
After making a DNS change you can clear the DNS cache on your device to hopefully see the DNS change sooner, this is not guaranteed to work since DNS changes are not instant but many situations can benefit from clearing the DNS cache:

How to Clear DNS Cache on Your Device

Overview

This guide explains how to clear the DNS cache on your computer or device to see DNS changes immediately, rather than waiting for DNS propagation and TTL (Time To Live) timeouts.

Why Clear DNS Cache?

After making DNS changes (like pointing your domain to a new server), your device may still use the old cached IP address. Clearing the DNS cache forces your device to fetch the new DNS information immediately instead of waiting for the cache to expire naturally.

When to Clear DNS Cache

  • After changing DNS records for your domain
  • When a website isn't loading after DNS changes
  • If you're seeing an old version of a website after migration
  • When troubleshooting connectivity issues
  • After switching hosting providers

Accessing Your Hosting Account

If you need to make DNS changes first:

  1. Login to the iFastNet client portal at: https://ifastnet.com/portal/clientarea.php
  2. Or use direct cPanel access at: https://yourdomain.com/cpanel (replace with your domain)

Need Support? Create a support ticket at: https://support.ifastnet.com/login.php Note: First-time users will need to register an account to create tickets.

How to Clear DNS Cache by Operating System

Windows 10/11

Method 1: Command Prompt

  1. Press Windows Key + R to open Run dialog
  2. Type cmd and press Ctrl + Shift + Enter (run as administrator)
  3. Type the following command and press Enter:
ipconfig /flushdns
  1. You should see: "Successfully flushed the DNS Resolver Cache"
  2. Close the command prompt

Method 2: PowerShell

  1. Press Windows Key + X and select "Windows PowerShell (Admin)"
  2. Type the following command and press Enter:
Clear-DnsClientCache
  1. Close PowerShell

Windows 7/8

  1. Press Windows Key + R to open Run dialog
  2. Type cmd and press Ctrl + Shift + Enter (run as administrator)
  3. Type the following command and press Enter:
ipconfig /flushdns
  1. You should see: "Windows IP Configuration successfully flushed the DNS Resolver Cache"
  2. Close the command prompt

Mac OS

For macOS Big Sur (11.0) and Later

  1. Open Terminal (found in Applications > Utilities)
  2. Type the following command and press Enter:
sudo dscacheutil -flushcache; sudo killall -HUP mDNSResponder
  1. Enter your admin password when prompted
  2. Close Terminal

For macOS Catalina (10.15) to High Sierra (10.13)

  1. Open Terminal
  2. Type the following command and press Enter:
sudo killall -HUP mDNSResponder
  1. Enter your admin password when prompted

For macOS Sierra (10.12) and Earlier

  1. Open Terminal
  2. Type the following command and press Enter:
sudo dscacheutil -flushcache
  1. Enter your admin password when prompted

Linux (Ubuntu/Debian)

For systemd-resolved (Ubuntu 18.04+)

  1. Open Terminal
  2. Type the following command and press Enter:
sudo systemd-resolve --flush-caches
  1. Enter your password when prompted

For nscd Service

  1. Open Terminal
  2. Type the following command and press Enter:
sudo /etc/init.d/nscd restart
  1. Or alternatively:
sudo service nscd restart

For dnsmasq

  1. Open Terminal
  2. Type the following command and press Enter:
sudo /etc/init.d/dnsmasq restart

Android Devices

Method 1: Restart Device (Easiest)

  1. Hold the Power button
  2. Select Restart or Reboot
  3. Wait for device to restart

Method 2: Reset Network Settings

  1. Go to Settings
  2. Navigate to General Management or System
  3. Select Reset or Reset Options
  4. Choose Reset Network Settings
  5. Confirm the reset (this will also reset WiFi passwords)

Method 3: Airplane Mode Toggle

  1. Open Settings
  2. Turn on Airplane Mode
  3. Wait 30 seconds
  4. Turn off Airplane Mode

iOS Devices (iPhone/iPad)

Method 1: Restart Device (Recommended)

  1. Hold Power button and Volume button simultaneously
  2. Slide to power off
  3. Wait 30 seconds and turn device back on

Method 2: Reset Network Settings

  1. Go to Settings
  2. Navigate to General
  3. Scroll down and select Transfer or Reset iPhone/iPad
  4. Select Reset
  5. Choose Reset Network Settings
  6. Enter your passcode
  7. Confirm the reset (this will reset WiFi passwords)

Method 3: Airplane Mode Toggle

  1. Open Settings
  2. Turn on Airplane Mode
  3. Wait 30 seconds
  4. Turn off Airplane Mode

Browser-Specific Cache Clearing

Chrome

  1. Press Ctrl + Shift + Delete (Windows) or Cmd + Shift + Delete (Mac)
  2. Select All time from the time range
  3. Check Browsing history and Cached images and files
  4. Click Clear data

Firefox

  1. Press Ctrl + Shift + Delete (Windows) or Cmd + Shift + Delete (Mac)
  2. Select Everything from the time range
  3. Check Cache and Cookies
  4. Click Clear Now

Safari (Mac)

  1. In Safari menu, select Develop > Empty Caches
  2. If Develop menu is not visible, go to Safari > Preferences > Advanced > Show Develop menu

Verifying DNS Changes

Using Command Line Tools

Windows/Mac/Linux - nslookup

nslookup yourdomain.com

Windows/Mac/Linux - ping

ping yourdomain.com

Online DNS Checking Tools

Use online DNS propagation checkers to verify your changes have propagated globally:

  • Check multiple locations worldwide
  • Verify all DNS record types (A, CNAME, MX, etc.)

Troubleshooting

If DNS Cache Won't Clear

  1. Restart your device completely
  2. Try a different network (mobile hotspot vs WiFi)
  3. Use a different DNS server temporarily (like 8.8.8.8 or 1.1.1.1)
  4. Check if changes have propagated using online tools

If Website Still Shows Old Content

  1. Clear DNS cache using methods above
  2. Clear browser cache and cookies
  3. Try accessing the site in incognito/private browsing mode
  4. Try a different browser or device

Still Having Issues?

  • DNS propagation can take up to 48 hours worldwide
  • Some ISPs cache DNS longer than others
  • Contact your hosting provider if DNS records appear incorrect

Summary

  • DNS cache stores old IP addresses that may prevent you from seeing changes
  • Clearing DNS cache forces your device to fetch new DNS information
  • Methods vary by operating system and device type
  • Browser cache may also need clearing for complete results
  • Restart your device if other methods don't work

Remember that even after clearing your local DNS cache, global DNS propagation can still take time as the changes spread across internet providers worldwide.