How to Flush DNS and Get New Dynamic IP

by on March 20th, 2009

renew ip, Flush DNS

Some times it is necessary to flush DNS to refresh internet services you are using in case of any service interruption. Flush DNS to get a new name resolution. Also flush DNS cache when you can’t access a newly registered domain name. You can simply flush your computer DNS cache anytime to get new entry. We discuss here that how can we flush DNS using MAC, PC or Linux and how to get a new dynamic IP address from IP server in Windows.

Requesting New IP Address

Flush DNS and request a new IP address from your ISP server by following these steps.

  • Click Start
  • Click run
  • In the run box type cmd.exe and click OK
  • When the command prompt opens type the following. ENTER after each new line.
  • ipconfig /flushdns
    ipconfig /release
    ipconfig /renew

The Commands are:


Fluch DNS

Fluch DNS for Windows

To flush DNS cache in Microsoft Windows (Win XP, Win ME, Win 2000) follow these steps.

Start -> Run -> type cmd
- in command prompt, type ipconfig /flushdns
- Done!

Fluch DNS for Linux

flush the DNS cache in Linux, restart the nscd daemon.

- To restart the nscd daemon, type /etc/rc.d/init.d/nscd restart in your terminal
- Run the command and linux DNS cache will flush.

Fluch DNS for MAC OS X Leopard

flush the DNS cache in Mac OS X Leopard by following these steps.

- type lookupd -flushcache in your terminal to flush the DNS resolver cache.
ex: bash-2.05a$ lookupd -flushcache
- Once you run the command your DNS cache (in Mac OS X) will flush.

Fluch DNS for MAC OS X

flush the DNS cache in Mac OS X by following these steps.

- type dscacheutil -flushcache in your terminal to flush the DNS resolver cache.
ex: bash-2.05a$ dscacheutil -flushcache
- Once you run the command your DNS cache (in Mac OS X Leopard) will flush.


6 Reviews

  1. DNAAND says:

    @aj: your DNS server has leased the IP address to your computer for a specified period of time, and if you “release” and “renew”, your PC releases your ip address and then asks the DNS server for an ip address…and, if you are still within the previous lease period, your DNS server will give you back the same IP address you previously had…so, when you type: ipconfig renew, you are actually just renewing the lease on your current ip address…you are not renewing the ip address itself. The length of the time for your IP address lease is set by the administrator of your DNS server. The only thing you can do, to get a different IP address is to change the MAC address on your NIC.

  2. Hiroshi says:

    @aj: You probably have static IP address. The above method works for the dynamic IP address. Check with your ISP.

  3. aj says:

    it didn’t give me a new ip address (comcast)

  4. Flush DNS says:

    In newer versions of Windows you need to run the command window in admin mode otherwise the flush will fail

  5. SEM-N-SEO says:

    Thanks for this useful info. It really worked out well for me.

  6. FourPx says:


    Thanks for the info…. I found it really helpful…


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