topic Re: 5508 and dynamic vlan assignement in Wireless

5508 and dynamic vlan assignement

g.billios — Sun, 04 Jul 2021 02:17:09 GMT

Hello,

I'm trying to setup a 5508 to work with dynamic vlan assignement using the same SSID.

I've followed everyting in this document http://www.cisco.com/en/US/tech/tk722/tk809/technologies_configuration_example09186a008076317c.shtml

but it doesn't work, every client independent of the RADIUS group is assigned to the same VLAN.

The only difference I have with that document is the [081] Tunnel-Private-Group-ID for which I use a string (nessesary for the LAN switches which use the same RADIUS) instead of a number.

What I see when sniffing the RADIUS traffic, every option is sent correctly to the WLC, from the WLC side and using the debug aaa events enable option I see nothing interesting.

Any ideas?

Thanks

George

Re: 5508 and dynamic vlan assignement

Nicolas Darchis — Thu, 14 Oct 2010 13:14:45 GMT

Hi George,

yes few ideas :

1) You need to enable AAA override in the ssid advanced settings. Not sure if you did it but always good to check.

2) You cannot send vlan name to the WLC. How is it suppose to know which vlan that is ?

3) What you need to send back is the vlan number and you must also have configured a dynamic interface on the WLC that is on that vlan.

With this, it should be working fine.

Nicolas

Re: 5508 and dynamic vlan assignement

g.billios — Thu, 14 Oct 2010 13:28:47 GMT

Thanks for the answer, below are my comments.

1) It is already enabled

2) Here is also my main concern. WLC should be able to accept text for vlan assignement since Cisco switches do so, they map the VLAN description to the test that ACS sends. Maybe I need to open a TAC ticket to verify this.

But in any case this should only be a problem if you use purely the IETF RADIUS attributes to pass the VLAN to WLC, in this case I also use the Cisco Airespace [VSA (Vendor-Specific)] attribute which certainly accepts the Interface name of WLC as an argument.

3) Dynamic interface is correctly configured in the WLC.

Today I will also try to update our WLC to version 6.0.199.4 from 6.0.196.0 since there is a resolved issue involving the proper function of AAA Ovveride, maybe that is the problem, will update when I do it.

BR,

George

Re: 5508 and dynamic vlan assignement

g.billios — Fri, 15 Oct 2010 07:56:17 GMT

A bit more debugging gave me this:

*Oct 15 09:31:28.491: xx:xx:xx:xx:xx:xx Received Tunnel-Group-ID Attribute -- ignoring AES Interface-Name '200' for STA xx:xx:xx:xx:xx:xx.
*Oct 15 09:31:28.491: xx:xx:xx:xx:xx:xx Tunnel-Type 16777229 should be 13 for STA xx:xx:xx:xx:xx:xx

(xx:xx:xx:xx:xx:xx is the client mac address)

It seems that:

1. WLC ignores the [14179\005] Aire-Interface-Name parameter regardless of what the value is (I have tried the vlan number, the interface name etc)

2. the second error is that the tunnel-type 16777229 should be 13. The tunnel-type has the value VLAN as required according to the Cisco document and in general for this to work. Funny thing is that RFC2868 doesn't define a value of 13 but RFC3580 define VLAN as value 13 so again I've set the correct value.

So I don't really know what to do now. I guess I have to open a TAC ticket.

Re: 5508 and dynamic vlan assignement

Nicolas Darchis — Fri, 15 Oct 2010 09:03:07 GMT

It sounds to me like it's ignoring the interface name attribute because you are pushing also the other attributes like Tunnel-group-ID.

If you push the tunnel type "vlan" and the tunnel-id, it will expect to get an attribute with the vlan number and thus ignores the AES interface name. did you try only sending the AES interface name ?

Nicolas

Re: 5508 and dynamic vlan assignement

g.billios — Fri, 15 Oct 2010 09:16:26 GMT

That might be the reason but as I wrote previously this setup also serves many switches thus I can't change the configuration without affecting the switches.

Also setting up another ACS just because the WLC doesn't understand some values is an overkill (taking also into account that I have to issue a certificate because of dot1x authentication etc).

In any case WLC should understand VLAN the [081] Tunnel-Private-Group-ID when using text because according to the RFCs this is a string value after all.

I am afraid that for the time being I have to freeze this and contact Cisco for a definitive answer.

Thanks for you input, if anything else comes in mind don't hesitate to reply

Re: 5508 and dynamic vlan assignement

Nicolas Darchis — Fri, 15 Oct 2010 09:26:20 GMT

I won't debate the format of attribute 81 as I didn't check that point in details, so I avoid to say stupid things 🙂

But for the rest, it's not "attributes that WLC doesn't understand". It gets attributes that indicate an IETF vlan number is pushed + attribute saying an interface name is pushed. It has to ignore one of the 2 right ? So that behavior looks correct to me.

How about using a NAP if you have ACS 4 or simply creating a service policy if you have ACS 5 ? that would allow you to differentiate attributes you send back to switches and to WLCs.

Regards,

Nicolas

Re: 5508 and dynamic vlan assignement

g.billios — Fri, 15 Oct 2010 09:30:56 GMT

Sorry, I didn't phrase it properly, ignoring one way of VLAN assignement is undestandable, I was only referring on how it understands the VLAN id value.

NAP can be a solution which I didn't think, will certainly try it and report the results.

Thanks

Re: 5508 and dynamic vlan assignement

g.billios — Mon, 18 Oct 2010 06:18:41 GMT

So I tried to use NAP and send to the WLC the VLAN id as a number and here is what I get:

Tunnel-Type 16777229 should be 13

Also tried to only send the interface name and again doesn't work.

So now I've really hit a brick wall. TAC is probably the only way to go now.

Re: 5508 and dynamic vlan assignement

g.billios — Tue, 19 Oct 2010 05:23:57 GMT

I found the problem after all: H-REAP !

Dynamic VLAN assignement doesn't work with H-REAP, it's written in the H-REAP documentation and somehow I missed it!