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why dhcp_lease_time default value is 120s?

asked 2013-10-16 01:07:59 -0500

maoliping455 gravatar image

In dhcp agent the default value of dhcp_lease_time is 120, this means the lease time is 120s, why we use such a short time? why do not we use 24 hours or some other longer time ? Thanks.

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answered 2013-10-17 05:49:08 -0500

gongysh gravatar image

The long time will have a side effect: If I update the port's IP via API, and the VM will not be updated until the long timeout.

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answered 2013-12-05 04:46:29 -0500

@Yong sheng

i agreed.

and it can be affected to live migrated vm ( like some one using multiple gateway and zones, it will take time to notice the gateway ip is changed by dhcp timeout)

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answered 2013-10-16 06:25:54 -0500

The lease time was low because previously the neutron-dhcp-agent didn't have a way to release the lease until it timed out. In the havana release the lease time is set to 24 hours though and the ip address can be reclaimed after a port is deleted.

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answered 2013-10-16 08:38:36 -0500

maoliping455 gravatar image

Thanks Aaron Rosen, that solved my question.

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Asked: 2013-10-16 01:07:59 -0500

Seen: 163 times

Last updated: Dec 05 '13