FlexConnect Overview
FlexConnect (formerly H-REAP) allows branch office APs to switch client data traffic locally at the remote site while the control plane remains with the Wireless LAN Controller (WLC) at the central site. This architecture reduces WAN bandwidth consumption, improves resiliency during WAN outages, and enables distributed branch deployments without requiring a controller at every site. FlexConnect APs communicate with the WLC over CAPWAP control channel (UDP 5246) while data traffic can be switched either centrally (tunneled back to the WLC) or locally (switched at the AP).
FlexConnect Modes of Operation
- Connected Mode: AP has an active CAPWAP tunnel to WLC. All authentication and policy decisions flow through the controller.
- Standalone Mode: AP has lost connectivity to WLC. Locally switched SSIDs remain operational. Clients can still authenticate using locally cached credentials or local EAP.
- Authentication-Central / Switch-Central: Traditional CAPWAP operation, data tunneled to WLC.
- Authentication-Central / Switch-Local: Authentication via WLC, data switched locally at AP.
- Authentication-Local / Switch-Local: Both authentication and switching happen at the AP. Required for standalone mode survivability.
FlexConnect Groups
FlexConnect Groups allow you to centrally configure settings that apply to multiple FlexConnect APs at a branch, including backup RADIUS servers, local EAP authentication, CCKM/OKC fast roaming, local users, VLAN-to-SSID mappings, and WLAN-VLAN overrides. Up to 100 APs per FlexConnect group on AireOS WLCs.
Fast Roaming in FlexConnect
| Roaming Method |
Description |
Scope |
| CCKM | Cisco Centralized Key Management, proprietary | Within FlexConnect Group |
| OKC | Opportunistic Key Caching | Within FlexConnect Group |
| 802.11r FT | Fast BSS Transition, standards-based | Within FlexConnect Group |
| PMK Caching | Sticky key caching on same AP | Per-AP |
VLAN Mapping and Native VLAN
For locally switched WLANs, FlexConnect APs map each WLAN to a specific VLAN on the local switch. The switchport connecting the AP must be configured as an 802.1Q trunk with the AP's management interface on the native VLAN.
! Catalyst switch configuration for FlexConnect AP
interface GigabitEthernet1/0/10
description FlexConnect AP Branch Site
switchport mode trunk
switchport trunk native vlan 10
switchport trunk allowed vlan 10,20,30,40,50
spanning-tree portfast trunk
no shutdown
!
Configuring FlexConnect on AireOS WLC
! Enable FlexConnect mode on an AP
(Cisco Controller) > config ap mode flexconnect AP-BRANCH-01
! Create a FlexConnect Group
(Cisco Controller) > config flexconnect group BRANCH-GROUP add
! Add AP to FlexConnect Group
(Cisco Controller) > config flexconnect group BRANCH-GROUP ap add AA:BB:CC:DD:EE:FF
! Enable local switching on WLAN 2
(Cisco Controller) > config wlan flexconnect local-switching 2 enable
! Map WLAN 2 to VLAN 20 on the AP
(Cisco Controller) > config ap flexconnect vlan wlan 2 20 AP-BRANCH-01
! Enable VLAN support on the AP
(Cisco Controller) > config ap flexconnect vlan enable AP-BRANCH-01
Split Tunneling
Split tunneling allows specific traffic (defined via ACL) to be switched locally while the rest is tunneled to the WLC. This is commonly used with OEAP (Office Extend AP) deployments for teleworkers, where corporate traffic tunnels to HQ but Internet-bound traffic egresses locally.
! Create split tunnel ACL
(Cisco Controller) > config flexconnect acl create SPLIT-TUNNEL-ACL
(Cisco Controller) > config flexconnect acl rule add SPLIT-TUNNEL-ACL 1
(Cisco Controller) > config flexconnect acl rule source address SPLIT-TUNNEL-ACL 1 10.0.0.0 255.0.0.0
(Cisco Controller) > config flexconnect acl rule action SPLIT-TUNNEL-ACL 1 permit
(Cisco Controller) > config flexconnect acl apply SPLIT-TUNNEL-ACL
! Apply split tunnel ACL to WLAN
(Cisco Controller) > config wlan flexconnect split-tunnel 5 enable
(Cisco Controller) > config wlan flexconnect split-tunnel acl 5 SPLIT-TUNNEL-ACL
OfficeExtend AP (OEAP)
OEAP provides secure corporate WLAN access for teleworkers. The AP at the home office forms a DTLS-encrypted CAPWAP tunnel over the Internet to the corporate WLC in the DMZ. Key features:
- DTLS encryption of data and control planes (UDP 5246/5247)
- Personal SSID for home use (unencrypted tunnel)
- Corporate SSIDs tunneled back to HQ
- Split tunneling for local Internet breakout
- Supported on 1810/1815/1830/1850/2800/3800/4800 APs with OEAP feature
- Requires WLC in DMZ with public IP or NAT
FlexConnect ACLs
FlexConnect ACLs can be applied at the VLAN level, WLAN level, or per-client via AAA override. They filter traffic at the AP for locally switched WLANs. Rules support source/destination IP, protocol, and port matching.
AP Upgrade and Image Predownload
! Enable FlexConnect AP image upgrade (master AP)
(Cisco Controller) > config flexconnect group BRANCH-GROUP predownload enable
(Cisco Controller) > config flexconnect group BRANCH-GROUP master-ap AA:BB:CC:DD:EE:FF enable
! Check predownload status
(Cisco Controller) > show ap image all
The master AP downloads the image from the WLC once, then distributes it to slave APs in the group over the local LAN, dramatically reducing WAN bandwidth during upgrades.
FlexConnect Design Considerations
- Maximum WAN latency between FlexConnect AP and WLC: 300 ms (100 ms recommended)
- Minimum WAN bandwidth per AP: 128 kbps (control plane only in locally switched mode)
- Up to 25 APs in standalone mode for authentication-local/switch-local WLANs
- Local EAP supports LEAP, EAP-FAST, PEAP, and EAP-TLS
- DHCP must be available at the branch for locally switched clients