Fast Switching is a feature offered in Cisco APs with RLAN support (9105WP AP from Cisco IOS-XE 17.15.2). The Remote LAN Fast Switching is introduced to improve LAN performance by bypassing CPU processing of user data packets in Local Switching mode. Instead of forwarding the data packets to CPU, the VLAN tagged data packets will be switched and forwarded between the WAN and LAN ports.
Configuring Fast Switching in 9800 WLC
The fast switching knob can be enabled here- Configuration>AP Join>AP Join profile>AP> General>Fast switching
AP/WLC CLI commands for verifying Fast Switching
WLC#show ap profile name <PROFILE_NAME> detailed | i Fast Switching
AP# show config rlan | i LanFastSwitching
Caveats for Fast Switching
- Fast Switching is only supported with local switching (no support for central switching)
- With Fast Switching enabled, AP and WLC cannot display client stats/information on CLI/WebGUI
- Following features are not supported with Fast Switching enabled- ACL, 802.1x, QoS, WebAuth, AAA overrride, Split Tunnel.
- When RLAN Fast Switching is enabled, the internal hardware switch in 9105WP AP automatically gets configured to trunk mode because of support for multiple VLANs. Therefore, the switchport where AP is connected to, should be configured as trunk port. If the switchport is configured as access port, then the AP will not get network connectivity.
Related Blogs–
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