DHCP reservation

[Marius Gunnerud]

From my understanding configuring an exclusion will require you to manually enter a static IP on a device and a reservation will not take effect. So my question is that if you need to create two DHCP pools, one for the lease and one for the reservation, how does the lease pool understand not to issue out that specific IP address when the device that is to receive the reservation is not connected to the network?

[mrdogantr]

Hi,

     look links below.

http://www.cisco.com/en/US/tech/tk648/tk361/technologies_tech_note09186a00800f0804.shtml

http://www.cisco.com/en/US/docs/ios/12_2/ip/configuration/guide/1cfdhcp.html

for example;

ip dhcp excluded-address 172.16.2.1 172.16.2.10
 ip dhcp pool TEST 

 network 172.16.2.0 /24

 default-router 172.16.2.1

 dns-server 8.8.8.8 

 lease 30

ip dhcp pool Test_User 

 host 172.16.2.254 

 hardware-address aaaa.bbbb.cccc

 client-name Test_User

hth

Muammer

[Marius Gunnerud]

My question is not how to configure a reservation but what is preventing the original DHCP pool to lease out the reserved address. For example using your example. What is preventing DHCP pool TEST from leasing out 172.16.2.254 when that machine is not connected to the network? Does the Test pool inspect other pools for reservations?

[cadet alain · Accepted solution]

Hi,

The lease is infinite once it has been allocated to host, you can see it in sh ip dhcp bind output.

Regards.

Alain.

[Marius Gunnerud]

Ah ok I see. Thanks for clearing this up for me!

[mrdogantr · Accepted solution]

most specific config (hardware-address, excluded-address) using  for the ip leasing