Wireless Access

Hi all,

I've been performing some low level testing of the AP join process to improve my understanding of the process involved. Whilst it is well documented in these forums in existing posts, I have come across a rather stange scenario that I'm struggling to understand.

The scenario I have created is this:

I have a single controller configured with a single Vlan172. This Vlan is defined as my controller-ip, has a layer 2 interface defined, 172.31.248.2. I have also defined a DHCP scope that does not have any DHCP options configured, it is just providing an IP address for the AP. On the controller I have also disabled ADP discovery and ADP igmp-join. The issue I have is when consoled into the AP I see the AP correctly obtain an IP address, and it states that it is running ADP and finds the master? In Wireshark I see the AP using ICMPv6, and still issuing multicast requests, what I don't see is anything coming back from the AMC. The AP is then able to join the controller. It is obviously layer 2 adjacenet to the AMC, but I can't figure out how it has joined?

Can somebody please explain? I know this is very basic, I'df just like a full understanding :)

Thanks

Do you have a DNS server configured with an "Aruba-Master" A-record?

Secondly, console into the AP and stop it at the apboot> prompt.  Type DHCP and press enter.  Please post the output.

Sure, will do

Also, on the controller, what is the output of "show adp config"?

Hi,

Output as requested...

Attachment(s)

Capture.txt   8 KB 1 version

Right, ok.

So in the attached I have provided my DHCP config on the controller and the output of the DHCP DORA between the AP and the AMC. I can see option 60 being returned by the controller, but not option 43, I thought it was option 43 that defined the IP for the AP use to terminate the tunnel on? Is there a different option included in the offer that it uses? The only one I can see is option 54 which I don't have configured in my scope.

Can you please elaborate on how this works just to clear it up in my mind?

Attachment(s)

dhcp-cfg.txt   246 B 1 version

DHCP option 43 and 60 are both in the capture.  Please look at the option 43 field in ASCII.  That is hardcoded into the background of every dhcp lease on the controller

http://www.arubanetworks.com/techdocs/ArubaOS_64x_WebHelp/Web_Help_Index.htm#ArubaFrameStyles/DHCP_Option_43/Windows_Based_DHCP_Serve.htm?Highlight=dhcp option

Ah yes, I see.

Thanks for clearing this up! :)

So in my example, as the controller has received this information in a DHCP offer it is not actually using ADP to find the controller. It is using the options provided in the lease (43/60). It is just a little confusing the output from the AP, as it suggest it has run ADP and found the controller using this method.

Yes, it is...

Hi,

No, all I have in my lab is my 3600 and a Cisco switch. No DNS. I had an old version of code on it originally so upgraded to 6.4.2.13 but get the same result. It is odd as in my production networks I don't see this.

Going back to it tonight so can post the output from the AP and packet capture from port and to the controller.

I wasn't sure if when the AP suggested it had run ADP that this was what it had actually used to find the AMC, and there wasn't another process running in the background. If there is, I didn't see this in the capture. I also reset the AP back to factory defaults (AP225) to rule this out. But got the same.