n3s0 || journal

    Windows: Release/Renew DHCP and Flush DNS Using CLI/PowerShell

    Posted on 2 mins

    PowerShell Windows

    Table of Contents

    Summary

    Just some notes. I have my days where I do this a lot. But, just in case I don’t and forget down the road. Might as well have this available.

    These are generally useful when I’m troubleshooting DHCP issues and IP issues on Windows workstations. I haven’t provided any output. But, if I feel it’s needed. I will soon.

    I’ll update this with any other useful commands.

    Note that all commands will need to be executed as Administrator.

    Showing IP Information

    I’ll provide a quick link to how to show your IP interface information on Windows systems soon.

    Release

    Sends a DHCPRELEASE message to the DHCP server on the network. This will release the current DHCP configuration; discarding the IP configuration for all adapters on the system.

    This operation is only performed on all adapters that are configured to obtain an IP configuration automatically.

    ipconfig /release

    Renew

    Renews the DHCP configuration for all adapters on the system. Will do so for all adapters on the system configured to obtain an IP configuration automagically.

    ipconfig /renew

    FlushDNS

    Flush the DNS resolver cache on the local system. This will discard invalid/broken entries that have been added to the DNS cache dynamically.

    ipconfig /flushdns

    Conclusion

    That concludes the notes for today. This is generally a troubleshooting step when you’re troubleshooting DHCP on a Windows network interface. Should be useful in the future.