Configuring Multi-VLAN on CBW140AC Access point

[fabios]

Dear all,

sorry if this is too trivial but I am new to Cisco WiFI and I am stuck trying to configure 3 CBW140AC in a non mesh configuration supporting 2 SSID mapped to 2 different VLANs.

Network:

The back end network is a Cisco 1921 Router and multiple Cisco 3560 gigabit PoE switch interconnected with Gigabit trunk links. The 1921 is running DHCP and the 3560 providing access port and PoE. There are 6 VLAN running on the network of which 2 should be associated with (distinct) SSID on all three access points. All access points are wired with CAT 6 and Cisco CDP shows correct neighborough relationships with switches router and APs. I did get the access point up and running, mapped one as preferred primary and achieved broadcasting of the SSID mapped to the native VLAN of the uplink switch port.

The point is (and I have read a couple of times the management guide for CBW) I do not know/understand how to:

-set the AP wired interface to trunk mode: If I set the corresponding switch port to trunk, I loose connectivity same for setting it as switchport mode dynamic preferred and finally setting it for access or dynamic auto the port stays in access mode (and non native VLAN traffic is not forwarded);

-map VLAN to SSID; I did try creating a RLAN and setting the RLAN VLAN tagging to yes and selecting the proper VLAN, then setting the WLAN in the same way but I cannot achieve the desired result; creating multiple WLAN without tagging cause all the client on the different WLAN to be mapped to the default (native) VLAN, setting it to VLAN tagging yes and the proper VLAN fails to establish connection (client is not assigned an IP address) DHCP works correctly.

I would appreciate a pointer to a configuration guide (like those available for IOS features if existing) explaining how VLAN,RLAN and WLAN are linked and managed and how to set the Gigabit Ethernet port of the AP in trunk mode (or negotiate trunk mode with the corresponding switch).

Thank you for your help.

Fabio

[thomask38420 · Accepted solution]

Hi Fabio,

i have not done this on CBW140AC before, but have on many mobility express models and the GUI looks similar. on those you just add the tag to the WLAN ssid config, so maybe this will help?

"Under the VLAN & Firewall tab, in the Use VLAN Tagging drop-down list, choose Yes to enable VLAN tagging of packets. Then, choose a VLAN ID from the drop-down list, to use for the tagging."

https://www.cisco.com/c/en/us/td/docs/wireless/access_point/mob_exp/810/user_guide/b_ME_User_Guide_810/specify_wireless_setgs.html

i think you can type in the vlan tag into the selection box if its not in list.

set the native to the same as you have on your switchport, and set tagging to no for a SSID that you want on the native vlan.

On 3560 side it may be best to set the switchport to a static trunk

#switchport mode trunk

# switchport trunk allowed vlan 2,3,4 (etc)

# switchport trunk native vlan 1 (for example)

from then the AP just tags the packet and sends it down the wire to the trunk port, no other config or trunk negotiation is used.  RLAN is used for extra wired ports on the AP, not WLAN.

hope this helps!

tom

[fabios · Accepted solution]

Hello Tom and thanks for your reply.

I was setting the interface to trunk mode but, since the configuration is done via WIFI, I was loosing network connectivity for the time the CBW was reconfiguring its interface from untagged to 802.1q tagged.

This is because I am used to configure IOS devices via console port which does not loose connectivity.

The best way to address this I found out is:

- provide initial config to CBW via the app while the CBW is connected to an untagged port where DHCP is available;

- connect via a wired interface to the upstream switch and reconfigure the port in switchport mode trunk setting the default VLAN to the native VLAN used for initial configuration of the CBW

- re-establish connectivity to the CBW via web interface from the wired computer used to reconfigure switch and then configure the multiple WLAN.

Configuring RLAN for each VLAN is unnecessary (only needed for additional Ethernet interface should you need to bring traffic for different VLAN on those and it is unsupported in mesh mode).

I found this gives me consistent result and little headaches

Hope this might be useful for others.

Cheers

Fabio