What command frees the prefixes from ipv6 local pools?

Answered Question
Jan 14th, 2010
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Hello,


    When I run the "show ipv6 local pool" command on my Cisco 6500 I'm getting the following output:


6500#sh ipv6 local pool
Pool                              Prefix                                      Free In use
client-prefix-pool1 2001:DB8:1200::/40                            18    238
client-prefix-pool2 2002:DB8:1200::/40                           254      2


   I would like to know what is the command which forcefully clears the prefixes from the pools so that I would have again 254 free prefixes in each pool.


My configuration is:


ipv6 dhcp pool dhcp-pool
prefix-delegation pool client-prefix-pool1 lifetime 1800 600
!
ipv6 dhcp pool dhcp-pool2
prefix-delegation pool client-prefix-pool2 lifetime 1800 600


ipv6 local pool client-prefix-pool1 2001:DB8:1200::/40 48
ipv6 local pool client-prefix-pool2 2002:DB8:1200::/40 48


interface GigabitEthernet3/5
no ip address
ipv6 enable
!
interface GigabitEthernet3/5.1
description downlink to clients
encapsulation dot1Q 4
ipv6 address FEC0:240:104:2001::139/64
ipv6 enable
ipv6 dhcp server dhcp-pool
!
interface GigabitEthernet3/6
no ip address
!
interface GigabitEthernet3/6.1
description downlink to clients
encapsulation dot1Q 5
ipv6 address FEC0:240:104:2002::140/64
ipv6 enable
ipv6 dhcp server dhcp-pool2



Thank you,

Ionut

Correct Answer by Sergei Vasilenko about 7 years 5 months ago

Hi Ionut,

Great it is working fine for you now.

If possible please mark this question as Answered then.


Thanks and Regards,

Sergey

Correct Answer by Sergei Vasilenko about 7 years 5 months ago

Hi Ionut,


Dependin on which platform/IOS version is in use

Could be a hit of bug CSCsa54564 not freed entries in ipv6 local pool.

In case of 6500  12.2(33)SXH or SXI the fix should be their already.


Regards,

Sergey

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Sergei Vasilenko Wed, 01/27/2010 - 06:49
User Badges:
  • Cisco Employee,

Hello Ionut,


Did you tried:


clear ipv6 dhcp binding []

http://www.cisco.com/en/US/docs/ios/ipv6/configuration/guide/ip6-dhcp.html#wp1055294

-----
From description:
This command deletes all automatic client bindings from the DHCPv6
database if is not specified; otherwise, only the
binding for the specified client is deleted.
-----


Thanks,
Sergey

ionut.gavaz Wed, 01/27/2010 - 06:57
User Badges:

Hi Sergey,


   Yes, I've tried this command several times . Although it seems that I do not have any DHCPv6 bindings, I cannot free the prefixes pools. Please check out below the commands' output:


6500#sh ipv6 dhcp bind


6500#clear ipv6 dhcp bind
6500#
6500#sh ipv6 local pool
Pool                Prefix                                      Free In use
client-prefix-pool1 2001:DB8:1200::/40                            18    238
client-prefix-pool2 2002:DB8:1200::/40                           254      2


Thanks,

Ionut

Correct Answer
Sergei Vasilenko Wed, 01/27/2010 - 07:15
User Badges:
  • Cisco Employee,

Hi Ionut,


Dependin on which platform/IOS version is in use

Could be a hit of bug CSCsa54564 not freed entries in ipv6 local pool.

In case of 6500  12.2(33)SXH or SXI the fix should be their already.


Regards,

Sergey

ionut.gavaz Wed, 01/27/2010 - 07:31
User Badges:

Hi Sergey,


   Since I'm using Version 12.2(18)SXF it is most probably a bug. I will upgrade my image as suggested as check out the behavior then(and also grade your response). Until then I will perform a cold start which should do the trick. I will keep you posted.


Thanks a lot,

Ionut

ionut.gavaz Mon, 02/01/2010 - 23:48
User Badges:

Sergey,


   After upgrading the IOS image I did not experience the same problem anymore. Thanks a lot for your support!


Regards,

Ionut

Correct Answer
Sergei Vasilenko Tue, 02/02/2010 - 00:56
User Badges:
  • Cisco Employee,

Hi Ionut,

Great it is working fine for you now.

If possible please mark this question as Answered then.


Thanks and Regards,

Sergey

ionut.gavaz Tue, 02/02/2010 - 01:13
User Badges:

Hi,


  I thought I did. Now it's showing as answered. Thanks a lot,again!


Regards,

Ionut

Ahmed M Alzaeem Mon, 10/22/2012 - 14:19
User Badges:

hi ,

i would like that i have the same issue on my router

i have router model 7200 and ios "advanceipservice"


the pool cant be cleared , 


this bug caused my system to get down >>>>>>> i configured an ipv6 addres to interace  with ip from the pool subnet that cant be removed .


after typing the command ,

the router hanged , and i have the error below:

=================================================

*Jun 13 15:01:48.901: %ENTITY_ALARM-6-INFO: ASSERT CRITICAL Gi0/1 Physical Port Link Down

LNS2#

*Jun   13 15:01:48.905: %ADJ-3-ADJSTACK2: Adj stack2 error IPV6 midchain out   of Virtual-Access1509 (incomplete): cannot stack on linktype requested:   l2x session stack to destination for : ,  -Traceback= 0x1934118z   0x19349C8z 0x1934B48z 0x1933FC0z 0x1934E70z 0x190B4FCz 0x18A2974z   0x18BD1A0z 0x19094ECz 0x190522Cz 0x190614Cz 0x18BF76Cz 0x18BF910z   0x6CAB2Cz 0x7561F0z

===========================================



as u see , it crashed


i think im in another trouble because reloading my router cost me very much



regards

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