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DHCP lease duration best time?

    Question

  • I am looking for some advice on DHCP Leases witch is the best time?

    I set my scavenging;

    • Time to No Refresh - 3 day
    • Refresh interval - 3 Day

    My AD is installed in Windows Server 2012, and i have 500 computers.




    Martha Sandoval


    • Edited by ahtrams Monday, August 26, 2013 10:49 PM
    Monday, August 26, 2013 10:29 PM

Answers

  • Hi,

    Based on my knowledge, when 50 percent of the lease duration has expired, the DHCP client automatically attempts to renew its lease from the DHCP server which the client obtained the lease. If fails, the DHCP client broadcasts a DHCPDISCOVER packet to update its lease when 87.5 percent of the lease duration expires.

    The DHCP lease time is eight days by default. You can adjust the lease to meet your needs.

    In general, if you are in a large network or have enough IP addresses in the DHCP scope for clients, you can increase the lease duration to reduce network traffic.

    If you have a limited number of IP addresses available, you may need to reduce the lease duration. Although reducing the lease duration creates more DHCP-related network traffic, it increases the rate at which addresses are returned to the available address pool for reassignment.

    More information about Scavenging, please refer to the following links:

    Understanding Aging and Scavenging

    http://technet.microsoft.com/en-us/library/cc771677.aspx

    Don't be afraid of DNS Scavenging. Just be patient.

    http://blogs.technet.com/b/networking/archive/2008/03/19/don-t-be-afraid-of-dns-scavenging-just-be-patient.aspx

    Best regards,

    Susie Long

    Thursday, August 29, 2013 10:18 AM

All replies

  • There is no real hard and fast rule on this.  Some people set a short period for environments with a lot of transient computers coming in and out and they have a limited pool of addresses to hand out.  This may be the case for a guest network.  There, it might make sense to drop the lease time to 4-8 hours.  In a data center server environment, the opposite is true.  A server gets an address and there is no real need to renew it on a regular basis.

    What are your business drivers?  Security for guests?  Make it shorter.  Reduction in network 'noise'?  Make it longer.  There can be other reasons, but they have more to do with business than with technology.


    .:|:.:|:. tim

    Tuesday, August 27, 2013 12:24 AM
  • Hi,

    Based on my knowledge, when 50 percent of the lease duration has expired, the DHCP client automatically attempts to renew its lease from the DHCP server which the client obtained the lease. If fails, the DHCP client broadcasts a DHCPDISCOVER packet to update its lease when 87.5 percent of the lease duration expires.

    The DHCP lease time is eight days by default. You can adjust the lease to meet your needs.

    In general, if you are in a large network or have enough IP addresses in the DHCP scope for clients, you can increase the lease duration to reduce network traffic.

    If you have a limited number of IP addresses available, you may need to reduce the lease duration. Although reducing the lease duration creates more DHCP-related network traffic, it increases the rate at which addresses are returned to the available address pool for reassignment.

    More information about Scavenging, please refer to the following links:

    Understanding Aging and Scavenging

    http://technet.microsoft.com/en-us/library/cc771677.aspx

    Don't be afraid of DNS Scavenging. Just be patient.

    http://blogs.technet.com/b/networking/archive/2008/03/19/don-t-be-afraid-of-dns-scavenging-just-be-patient.aspx

    Best regards,

    Susie Long

    Thursday, August 29, 2013 10:18 AM