asked on

Cisco 1852i Access Point not connecting to Controller or DHCP Server

I am trying to get the Cisco 1852AP to receive a DHCP address and as well as talk to the controller but unsuccessful:

I currently have a DHCP Server, WLC and the Cisco 1852AP all connected to my 3750 switch. The DHCP server is in Vlan 210 and the WLC is in vlan 101. I've tried everything from making both the Server and AP interfaces access and trunk ports but keep reciving the following error when consoled into the AP:

"waiting for uplink IP address and reachable default gateway"

I can successfully ping the DHCP server from my Controller

interface GigabitEthernet1/0/1
description WLC
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 101,210
switchport mode trunk
!
interface FastEthernet1/0/4
description Server
switchport access vlan 210
switchport mode access
!
interface FastEthernet1/0/5
description Access Point
switchport trunk encapsulation dot1q
switchport trunk allowed vlan 101,210
switchport mode trunk
no logging event link-status

interface Vlan101
ip address 172.10.108.65 255.255.255.192
ip helper-address 172.10.100.151
no ip redirects
no ip unreachables
no ip proxy-arp
!
interface Vlan210
ip address 172.10.100.1 255.255.255.0
ip helper-address 172.10.100.151
no ip redirects
no ip unreachables
no ip proxy-arp

Craig Beck

The AP port has no native VLAN. This should be set to the VLAN ID that you want the AP to be on. It can still be a trunk and the AP will trunk, but the AP's management traffic is untagged by default.

interface FastEthernet1/0/5
description Access Point 
switchport trunk encapsulation dot1q
switchport trunk native vlan 101
switchport trunk allowed vlan 101,210
switchport mode trunk
no logging event link-status
spanning-tree portfast

Open in new window

This is a standard FlexConnect configuration though. If the AP is going to be in Local mode instead of FlexConnect mode, configure the AP port as an access port instead.

interface FastEthernet1/0/5
description Access Point 
switchport access vlan 101
switchport mode access
no logging event link-status
spanning-tree portfast

Open in new window

solarisjunkie

ASKER

How can you determine whether it's in flex connect or local mode ?

I've tried putting it with the native vlan to no avail. I statically assigned an IP and was able to connect to the controller so does that tell me that the DHCP server may be configured without option 43 or is that truly needed.

Craig Beck

Out-of-the-box APs are usually in Local mode. You have to configure them to be in FlexConnect mode. In Local mode, you use an access port at the switch. In FlexConnect mode you usually use a trunk port at the switch.

If you configured an IP address on the AP, that doesn't necessarily mean it will join the WLC each time. In fact, with a static IP on the AP, if it doesn't join a WLC after a few minutes it will try to get the WLC IP via DHCP.

Have you verified that the AP can get an IP via DHCP while on the WLC VLAN?

solarisjunkie

ASKER

It doesn't pick up the ip from dhcp though when statically assigned I can see the ap on the controller which presents 2 other concerns. When I issue a show config while consoled into the ap it displays 0.0.0.0 for the wlc ip addresses and the image file is empty, but when I view the ap from the wlc it shows the image and other pertinent info...smh

Craig Beck

Ok, so you can't get an IP from the DHCP server in VLAN 210 while you're in VLAN 101...

Is the DHCP server using 172.10.100.1 as its default gateway or is it pointing at a different router?

solarisjunkie

ASKER

The DHCP server is on a VM but I can reach the DHCP from my controller which is on vlan101.

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