WLC 2500 - Newly configured Guest Wifi: Client is getting IPV6 instead of IPV4 from DHCP pool

[kobe12xx]

Hi Guys,

The client is getting IPV6 IP Address instead of IPV4 IP Address from the DHCP pool. Please see image below for reference.

Is there a workaround on this issue. 

Thank you.

[Sandeep Choudhary]

HI,

If you are not using IPv6 then you can disable on WLC:

Step 1 : Choose Controller > General.

Step 2 : From the Global IPv6 Config drop-down list, choose Disabled.

Step 3 : Click Apply.

Step 4 : Click Save Configuration.

Also make sure that you put the right DHCP server under dynamic interface which is assigned to Guest wlan.

Regards

Dont forget to rate helpful posts

[kobe12xx]

Still same issues. Any more areas where I can look into?

Isolate:

IPV6 is disabled 

DHCP server under dynamic interface - Configured correctly. 

[Haydn Andrews]

FE80 is a link local address, if IPv6 is disabled on the wireless side - check client side that IPv6 is also disabled.
Also confirm that DHCP is working for that SSID for other devices - as i have seen this if the client cant get an IPv4 before.

If AP is in flexconnect check VLAN mapping is correct as this will do it as well

[Leo Laohoo]

Look at "Auth" and it says "No".
This means that the VLAN is now allowed through the Trunk.

[kobe12xx]

Hi Leo,

Good catch! Please find below existing config and let me know if I can change and configure a trunk on the following interfaces.

*vlan 50 - management 

*vlan 77 - new guest wifi

Please advise if this is correct. Trunk sample config:

!
interface TenGigabitEthernet1/0/41
description **WAP**
switchport trunk allowed 50, 77
switchport mode trunk
!

!!!!!!! existing config !!!!!!! 

!
interface TenGigabitEthernet1/0/41
description **WAP**
switchport access vlan 50
switchport mode access
spanning-tree portfast
spanning-tree guard root
!
interface TenGigabitEthernet1/0/42
description **WAP**
switchport access vlan 50
switchport mode access
spanning-tree portfast
spanning-tree guard root
!

!
interface TenGigabitEthernet2/0/41
description **WAP**
switchport access vlan 50
switchport mode access
spanning-tree portfast
spanning-tree guard root
!
interface TenGigabitEthernet2/0/42
description **WAP**
switchport access vlan 50
switchport mode access
spanning-tree portfast
spanning-tree guard root
!

!
interface Port-channel20
description WLC
switchport mode trunk
!

!
interface TenGigabitEthernet1/0/39
description **WLC**
switchport mode trunk
channel-group 20 mode on
!

!
interface TenGigabitEthernet2/0/39
description **WLC**
switchport mode trunk
channel-group 20 mode on
!

Thanks 

[Leo Laohoo]

Post the complete output to the command "sh interface Ten 2/0/39 trunk".
Is VLAN 77 found in the VLAN database?

[kobe12xx]

Hi Leo,

Please see below config.

CORE-SW#sh vlan

VLAN Name 
---- --------------
77    Wireless-Guest-New active

CORE-SW#sh interface Ten 2/0/39 trunk

Port Mode Encapsulation Status Native vlan
Te2/0/39 on 802.1q trunk-inbndl 1
(Po20)

Port Vlans allowed on trunk
Te2/0/39 1-4094

Port Vlans allowed and active in management domain
Te2/0/39 1,10,14,20-21,25-26,30,35,40-41,45,50,55,60,70,77,80,88,90,95,100-101,401

Port Vlans in spanning tree forwarding state and not pruned
Te2/0/39 1,10,14,20-21,25-26,30,35,40-41,45,50,55,60,70,77,80,88,90,95,100-101,401

[Sandeep Choudhary]

Chekc the ports

See if you correctly configure dthe DHCP server IP

REgards

Dont forget to arte helpful posts

[kobe12xx]

What ports?

Yes DHCP server IP configured correctly.

[Leo Laohoo]

Check the DHCP pool. 

Check the DHCP scope.

Check the dynamic interface and make sure it is pointing to the correct DHCP server.