Router not releasing DHCP addresses, can I clear?

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Dec 29th, 2007
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I am using a Cisco 877, but I have noticed I get a new IP everytime, but the next one up, there are only 2 PC's on this router. I get an IP of 192.168.2.11, then tomorrow it will be 192.168.2.12, then 13, 14 etc, surely it should release the IP after a day or 2 and reuse the IP's at the beggining of the scope?


ip dhcp pool client

import all

network 192.168.2.0 255.255.255.0

default-router 192.168.2.100

dns-server 87.86.18.1 90.20.23.9 190.72.0.9

lease 0 2

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Overall Rating: 4 (1 ratings)
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tekha Sat, 12/29/2007 - 08:10
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Are you by any chance having filters on the interface?

I've seen this behavior before when applying an access-list to the interface of the DHCP clients.

jamesgonzo Sat, 12/29/2007 - 09:43
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Just cleared the arp, but my pc wants to continue to now have 192.168.2.20, why not 192.168.2.11 or 12 (the start of the DHCP scope)?

paolo bevilacqua Sat, 12/29/2007 - 09:47
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Actually I believe the IOS DHCP server will use linearly the pool unless the client requests an available address.

Do "show ip dhcp pool" to see which address will be handed out at the next request .

jamesgonzo Sat, 12/29/2007 - 10:05
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Here it is:

H0m3#sh ip dhcp pool


Pool client :

Utilization mark (high/low) : 100 / 0

Subnet size (first/next) : 0 / 0

Total addresses : 254

Leased addresses : 1

Pending event : none

1 subnet is currently in the pool :

Current index IP address range Leased addresses

192.168.2.21 192.168.2.1 - 192.168.2.254 1

H0m3#


paolo bevilacqua Sun, 12/30/2007 - 05:43
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Well,you should now be able to observe, as mentioned before, that the router allocated addresses in a linear fashion, spanning the full scope, unless the client request otherwise.

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