WLC not providing different DHCP pool addresses per WLAN/VLAN

[Ivan Mamka]

Hello,

Issue: I have 3 WLANs configured on a WLC with separate VLAN(100,101,150) for each. Also there is a management VLAN(100) which does not have WLAN created for it. When clients associate to Lightweight APs, they receive IP addresses which are part of management VLAN pool.

Wi-fi infrastructure overview:

WLC & 2 Lightweight APs setup with 4 different VLANs, 1 VLAN for management(100) and 3 VLANs(101,102,150) for 3 WLANs. DHCP is setup on core switch. WLC connected to a core switch with a trunk link and native 100 VLAN. There are two other access switches connected to core switch, which have both trunk links with native 1 VLAN. One Lightweight AP connected per one access switch with trunk links and native 100 vlan.

I'll attach a PT file, but see bellow core switch and one WLAN configuration. Also in PT there is not connected another general WLC which does not have https connection interface. With that WLC all worked as it should, thus I believe this is WLC misconfiguration.

WLC config overview:

Same problem exist for all 3 WLCs, so I'll describe config of one WLAN: guest

WLAN:

SSID: guest

Interface: guest

Layer 2 Security: None

INTERFACE: guest

VLAN ID: 150

IP address: 10.10.150.99

mask: 255.255.255.0

gateway: 10.10.150.1

primary dhcp: 10.10.150.1

Interface type: Dynamic

################################# Core Switch:

ip dhcp excluded-address 10.10.100.1 10.10.100.50
ip dhcp excluded-address 10.10.101.1 10.10.101.29
ip dhcp excluded-address 10.10.102.1 10.10.102.29
ip dhcp excluded-address 10.10.150.1 10.10.150.10

ip dhcp pool WLAN-AP
network 10.10.100.0 255.255.255.0
default-router 10.10.100.1
option 150 ip 10.10.100.99
dns-server 4.2.2.2

ip dhcp pool Vlan101
network 10.10.101.0 255.255.255.0
default-router 10.10.101.1
dns-server 4.2.2.2

ip dhcp pool Vlan102
network 10.10.102.0 255.255.255.0
default-router 10.10.102.1
dns-server 4.2.2.2

ip dhcp pool Vlan150
network 10.10.150.0 255.255.255.0
default-router 10.10.150.1
dns-server 4.2.2.2

interface GigabitEthernet1/0/5                "" connects to WLC ""

switchport trunk native vlan 100

switchport mode trunk

switchport nonegotiate

interface Vlan1

no ip address

shutdown

!

interface Vlan100

mac-address 0040.0b5a.4d01

ip address 10.10.100.1 255.255.255.0

!

interface Vlan101

mac-address 0040.0b5a.4d02

ip address 10.10.101.1 255.255.255.0

!

interface Vlan102

mac-address 0040.0b5a.4d03

ip address 10.10.102.1 255.255.255.0

!

interface Vlan150

mac-address 0040.0b5a.4d04

ip address 10.10.150.1 255.255.255.0

!

Thanks!

[Scott Fella · Accepted solution]

If your plan is to tunnel traffic back to the controller, the interfaces must reside on the controller and the AP’s are in local mode. If you want traffic to be placed on the switch where the ap is connected to, then you need to aps to be in FlexConnect mode and the wlan to be configured for local switching. Then your FlexConnect group would need to have the vlans defined that will be for the management (native) and also the users.
Usually when you see traffic getting placed on the native vlan, it’s because the mode is wrong and the wlan to vlan mappings are wrong.

[Ivan Mamka]

Hello Scott,

I enabled FlexConnect at WLAN -> corporate WLAN -> Advanced -> enable FlexConnect Local switching

That solved the problem! Thanks! Also I don't really understand what you meant by "FlexConnect group needing to have vlans defined....", but I guess that is not required in CCNA, will leave it for the future.

Cheers

[Scott Fella]

Well keep in mind that FlexConnect group allows for roaming between aps and consistent settings for aps in that group.