Trunking between a 1100 AP and a L3 switch

[m-avramidis]

Hi!

I`ve problem with setting up a trunk between a L3 switch (4006) and a Aironet 1100 AP. Below are a description of what I want to do:

I want to set up a wireless network, running together with our wired network, which uses the same VLAN`s as our wired networks. I`ve setting up, in a lab environment, the following: 1 2621 – interVLAN routing connecting via a trunk to a 4006 connecting to the AP via a trunk port. I `ve confirmed the following:

- that i`ve connectivity between the 2621 and the 4006 – Ping tests to the different VLAN`s

- that the VLAN`s (4) is “in” the VTP domain of the 4006 L3 switch, and that the trunk is working with the correct encapsulation.

- that the trunk port (to the AP) is correctly configured.

- that the encapsulation (dot1q) is configured on the AP

This does`nt work, but if i change the switch port (the port to the AP) to for an example VLAN 3 it works (and it works to ping the subinterfaces on the 2621 router, where the VLAN`s resides.

I`ve read the white papers on the 1100 series AP, but I get the impression that (and when I look at the pictures, the pictures shows “trunks” between a AP and a L3 switch) trunking is supported. But is that the same trunking technique as it is between 2 switches? Or is it something “special”? What I mean is if I can`t do the “usual” trunking between a switch port and a AP, I will end up spending up a lot of subnets of our IP network.

Does anyone have any solution to my/our problem?

[thomas.chen]

You can do the normal trunking betweeen the AP and the layer3 switch.What you came across the White papaers for 110 series AP is the same trunking. In fundamental terms, the key to configuring an access point to connect to a specific VLAN is by configuring its SSID to recognize that VLAN. Since VLANs are identified by a VLAN ID, it follows that if the SSID on an access point is configured to recognize a specific VLAN ID, a connection to the VLAN is established. When this connection is made, associated wireless client devices having the same SSID can access the VLAN through the access point. The VLAN processes data to and from the clients the same way that it processes data to and from wired connections. You can configure up to 16 SSIDs on your access point, so you can support up to 16 VLANs.

You can segment your wireless LAN user community and enforce a different security policy for each user group.

In you case make sure that you have followed the guidelines for configuring VLANs in an AP.

I have found a good document that will help you in configuring the same.

http://www.cisco.com/en/US/products/hw/wireless/ps430/prod_technical_reference09186a00801444a1.html

[m-avramidis]

Thanks.

What i found out was: the only way (at least i think so) to avoid spending up a lot of ip addresses is to do the following: configure the AP according the "cisco" way and create a BVI interface reflecting the VLAN`s that you created. For example: let`s say that you got 3 VLAN`s - 3,4 and 5, first configure it as it is done on the Cisco web site and then add (without any ip adresses): BVI 3, BVI 4 and BVI 5. After i did this, it worked without any problems

[dkuyper]

I'm running something similar, although my AP1100's are connected to 3548 Layer 2 switches and the routing is done by a 3550-12t. I had some similar problems with getting the AP to work with different VLAN's. Perhaps my solution will help:

For this I'm using VLAN 105 as my native VLAN (the VLAN that the BVI is configured for)

- configure the switch port as a dot1q trunk and set the trunk native vlan

switchport trunk encapsulation dot1q

switchport trunk native vlan 105

- configure the AP's FE interface as follows:

interface FastEthernet0.105

encapsulation dot1Q 105 native

If I didn't set the ports as 'native' it wouldn't work.

Hope that helps.

[m-avramidis]

Thanks.

What i found out was: the only way (at least i think so) to avoid spending up a lot of ip addresses is to do the following: configure the AP according the "cisco" way and create a BVI interface reflecting the VLAN`s that you created. For example: let`s say that you got 3 VLAN`s - 3,4 and 5, first configure it as it is done on the Cisco web site and then add (without any ip adresses): BVI 3, BVI 4 and BVI 5. After i did this, it worked without any problems