Controllerless Networks

Hello everyone,

we have 6 Aruba 205 APs and one of them also acts as a virtual WLC.

wanna to change the IP addressing of the APs and the Virtual IP of the WLC too(assign statically) because of a migration and have following queries:

should i change the IP addresses on APs first and do WLC's virtual IP as the last one?

will the APs know how to connect to a new Virtual IP of the WLC?

(Aruba Discovery Protocol (ADP) should be running based on the info i have from the link - https://www.arubanetworks.com/techdocs/ArubaOS_64_Web_Help/Content/ArubaFrameStyles/AP_Config/AP_discovery_ADP.htm)

will any reboot be required?

in case any additional info is needed please let me know.

thank you, erik

As long as the APs are on the same subnet/VLAN you should be good. All of the IAPs perform a master election, and any of the APs can take over as the Virtual Controller. You can prefer one to always become the Master when it is up. See image below. I personally would just change the IP on one of the IAPs, then change it to become the preferred master. Once that's done, change the IP's on the rest. You can also make sure that your VC has the same address no matter what IAP takes over with the following steps:

To specify name and IP address for the Virtual Controller:

1.) At the top right corner of the Instant UI, click the Settings link. The Settings window appears.

2.) Enter a name for the Virtual Controller in the Name text box.

3.) Enter the appropriate IP address in the Virtual Controller IP text box.

Hey Erik,

as long as the Instant APs remain in the same subnet (L2 broadcast domain), they will discover each other independently whether you configure their IP address statically or dynamically using DHCP. This happens through broadcast messages, that is why the IAP can only form a cluster in the same L2 broadcast domain.

Here is the Instant AP discovery logic explained: https://www.arubanetworks.com/techdocs/Instant_83x_WebHelp/Web_Help_Index.htm#Instant_UG/CustomizeIAPParams/IAP Discovery Logic.htm 

Unless you configure a preferred master AP in an Instant cluster, the first one to boot will automatically assume this role.

The Virtual Controller (VC) is tied to this master AP but can change to other APs in the swarm.

hello guys,

thank you both for your replies.

just wondering if any reboot of the APs will be required once the IP address is changed.

we might also turn of the APs because of physical reconnecting to the switch (not sure if they run only via PoE now).

is the configuration saved automatically once the details are configured?

thanks a lot,

appreciate your help,

erik

one more thing has come to my mind...if i change the IP on one of APs and set it to Master so it becomes the Virutal WLC, will i still have access to the rest of the APs for changing their IPs in the GUI?

thank you

Yes you can change the IP of the APs via the GUI. See screenshot:

Once you change the IP, the AP will have to reboot to apply the IP change. See below on how to reboot per AP:

 When you change settings in the Instant UI, the changes get saved automatically.

Hello Dustin-Burns,

thank you for the guide.

if i summarize the steps i need to perform, they'll be as following:

1) change the IP address of an AP that is not the Virtual WLC now

2) enable the AP to be a master

3) reboot the AP

4) change the IP address on the rest of the APs

5) reload the rest of the APs

would this procedure be correct?

thanks, erik

Yes that would work.

thanks a lot Dustin, appreciated!!!

will perform the migration on Saturday and let you know the result

cheers

hey guys,

one more thing that just come to my mind.

when is the time to connect the APs to to a new switch?

after re-addressing the first and making it a master?

or do you recommend another time?

thanks, erik

To be clear, it is highly discouraged to use static ip addressing on APs, either instant APs or controller based APs, for the reason you are mentioning; it will be difficult and painful to consider migrating access points one by one if a network has to be readressed or expanded.  We see customers using static addressing every day and we advise them to unwind that and use DHCP constantly.

If you are running an instant network, change them all to DHCP.  After you migrate the network, getting into the GUI of any Instant AP will redirect you to the master VC.  If you are running a campus-AP based network, just having them on the same layer 2 VLAN of the controller will allow them to discover the controller.

hello guys,

when i tried to change the IP of an AP and let it become as a master, it did not work (did also a reboot after these settings) :/

but once the IP address of the WLC has been changed the rest of the APs have discovered it and all was fine.

anyway, thanks for your comments.

erik