Setting Up HA for 5760 WLC

[raymondfong]

I'm trying to setup 2 units of 5760 wlc with HA for @100units AP3260I.

Questions on HA:-

1. Can the new 5760 wlc do HA-SSO ?

2. Another option documented is AP-SSO

I managed to configure the APs for primary and secondary controller mode but during the switch over, the client is disconnected and need to re-authenticate again.

Is there any sample setup configuration for controller HA as opposed to AP-SSO ?

I have been searching around but most of the documents are also talking about AP-SSO.

Appreciate any feedback.

[devils_advocate]

HA mode means both controllers share a Virtual IP address and all your Access Points associate with this.

You would only need a primary and secondary IP if you have a redundant set of HA controllers.

Going from primary to secondary controllers will cause the clients to disconnect and reconnect, thats normal but if running HA that shouldnt happen because of the single IP address shared between the controllers and they are stateful sync between them.

This is my understanding at least

[raymondfong]

hi devils_advocate,

Do you have any idea how to setup the HA on 5760 wlc ?

From documentation, it seems like this can't be done at the moment and the recommendation is to use AP SSO.

[Leo Laohoo]

High Availability (SSO) Deployment Guide, Release 7.5

[Viten Patel]

Release 7.5 for 5760?

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[raymondfong]

Yes.

I have setup both the controller with the same settings except for IP address.

The APs can swing to the secondary controller but I found that the secondary controller keeps timeout during ping and access is to the controller is very slow.

Is the secondary controller doing syncing with the primary controller ?

I cant find the setup for doing controller HA, so currently doing AP SSO.

[Leo Laohoo]

Release 7.5 for 5760?

Good point, Viten.

When is the HA feature going to be released for 5760?

[Ryan Jasper]

beginning of the month new code was released.  HA SSO is now supported though I think you will need to stack the controllers.

[a-weitzel]

Hello all

I am faced with the same problem. We want two WLC 5760 (spread over two locations) in HA mode running (like SSO), so that there is no significant loss during switching. Only I can not find any documentation to how this would work?

The WLC 5760 is available as a HA device (AIR-CT5760-HA-K9). Then it comes at the switchover, according to my understanding, a short cut?

Have you or anyone else the problem solved?

Thanks for your support

Alexander

[Thomas McClintic]

Alexander,

"It is highly recommended to have back-to-back direct connectivity between Redundant Ports."

That said, it should work if you can get a flat network to both locations for the keep-alives. I would be concerned about a random high latency or drop in connection causing HA to initiate.

Details of the failover:

The Standby WLC sends keep alive to the Active WLC and expects and acknowledgment within 100 msec as per the default timer. This can be configured in range from 100-400 msec.

If there is no acknowledgment of keep alive within 100 msec, the Standby WLC immediately sends an ICMP message to the Active WLC via the redundant management interface in order to check if it is a box failover or some issue with Redundant Port connection.

If there is no response to the ICMP message, the Standby WLC gets aggressive and immediately sends another keep alive message to the Standby WLC and expects an acknowledgment in 25% less time (that is, 75 msec or 25% less of 100 msec).

If there is no acknowledgment of keep alive within 75 msec, the Standby WLC immediately sends another ICMP message to the Active WLC via the redundant management interface.

Again, if there is no response for the second ICMP message, the Standby WLC gets more aggressive and immediately sends another keep alive message to the Standby WLC and expects an acknowledgment in time further 25% of actual timer less from last keep alive timer (that is, 50 msec or last keep alive timer of 75 msec - 25% less of 100 msec).

If there is no acknowledgment of the third keep alive packet within 50 msec, the Standby WLC immediately sends another ICMP message to the Active WLC via the redundant management interface.

Finally, if there is no response from the third ICMP packet, the Standby WLC declares the Active WLC is dead and assumes the role of the Active WLC.

Hope this helps

[Scott Fella]

With IOS XE 3.3.0SE AP SSO is supported when using the controller stack cable. So the 5760 and 5760-HA is in a stack and HA is enabled by default when stacked.

See the release notes.

http://www.cisco.com/en/US/docs/wireless/controller/5700/software/release/3se/release_notes/OL30703.pdf

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[a-weitzel]

Hi,

can you give me the documentation on this?

Stacking will probably not be possible because of the distance. A back to back over fiber optic cabling already.

cheers Alexander

[Scott Fella]

Stacking is the only way. Yo can still provide AP high availability and not have AP SSO.

http://www.cisco.com/en/US/docs/wireless/controller/5700/software/release/3se/consolidated_guide/configuration_guide/b_multi_3se_5700_cg_chapter_01101100.html

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