Synchronizing configuration between WLCs

[Julian Ortiz]

Hi everyone,

New to Cisco Wireless world, though experienced with other vendors. While studing the "Understanding Controller Discovery" chapter in the "CCNA Wireless OCG", I see several controllers can coexist within a network, and APs can move from one to another in case of failures. The idea is to have all the controllers with the same configuration in order to maintain the APs working the same before and after of a controller's failure (i.e. same SSIDs, same transmit power, etc.). How is this accomplished? One controller acts as master controller and pushes its configuration to the rest which act as slaves? Or is this done through Cisco Prime? Any idea?

Thanks in advance,

Julián

[Haydn Andrews]

All the controllers in the same mobility domain you will want to make sure the following are the same otherwise you will run into issues when an AP moves between them at a minimum:

WLAN IDs for each SSID, and their configurations

AP Groups

Flexconnect Groups

RF Profiles / RF Settings

The easiest way to make sure that all these are the same is using Prime, other options would be writing a script to push to each WLC

[patoberli]

As Haydn wrote, through Prime if you have many WLCs.
If it's just 2 or 3, you can also do it manually, just configure each WLC the same (besides Hostname and IP addresses).
If you use HA SSO, then the standby WLC with be synchronized with the Master WLC.

[Jonas Kalldert · Accepted solution]

Hi Julián.

As mentioned before prime is used to keep the WLC config synced between the controllers if you are running a N+1.
In a HA the config is synced between the WLCs but if I read your post correctly you are planning for a N+1 deployment.

So, for SSID's, AP-groups, RF-profiles, Flexconnect groups and when configure batches of APs Prime is a must in my opinion.

I also saw that you mentioned transmit power, I will include channel in this also. Power (TCP) and Channel assignment (DCA) is in most cases put as dynamic so the WLC will calculate what’s best for any given circumstances. This is not synced between the WLCs using prime. Instead the WLCs needs to have the same RF Group Name configured. That way they will decide on a RF Group Leader, so even if the APs on a site is on different WLCs they can decide on what power and channel they should use and coexist much better.
On top of that the WLCs should also be in the same Mobility domain so client databases and so on is synced between the WLCs for better client roaming in the case of a client roaming from one AP on WLC1 to an AP residing on WLC2.


regards,
Jonas
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[Julian Ortiz]

Hi guys,

Thanks very much for the clarification, much clear :)

Regards,

Julián