Wireless Access

Hello,

 

Does anyone have any info on implementing fail-over for APs to another Cluster? Simply adding a LMS backup IP (Cluster 2 VIP) in the AP group didnt work :D I know a bootstrap would occur I don't even see the AP in MM after powering off the cluster.

 

Additional info: I'm using DHCP options 43 and 60 for new APs.

 

Thanks,

Allan 

Are you powering off the cluster after the AP is connected to the cluster?

Yes I have two MCs in each Cluster. 

 

I powered off each Cluster member. Watched the A-AAC change to the S-AAC. 

Powered off the last MC of cluster. 

 

AP never reported into BLMS (VIP) of Cluster 2.

When you say " you don't even see the AP in the MM" what command are you using the see the AP in the MM?

Is there a specific guide on how AP Failover to another cluster should be configured? i.e. where is the hierarchy the AP-Groups, VLANs, and WLANs should be created? I can find articles stating it can be done using LMS and B-LMS, but no suggestions on the actual configuration.

Do you want to make an AP failover to a specific controller in the cluster?

 

For more information on how AP load balancing is configured, 

refer the AOS UG 8.5.0.0 (Page: 373)

Say I have 2 different datacenters, and a cluster in each datacenter. If datacenter 1 cluster goes down I want the APs that typically terminate to that cluster to failover to datacenter 2 cluster.

So the scenario is like this.

Datacenter 1 - cluster 1 - APs terminated on a controller in this cluster.

 

Datacenter 2 - cluster 2 - APs should failover to a controller in this cluster if the controller that the APs are terminated to on cluster 1 fails.

 

Try this solution

Cluster 1 - This will have a MC which acts as a LMS to the APs (say 10.0.0.1 )

Cluster 2-  Choose a controller which should act as a B-LMS to the AP when they fail over. (10.0.0.2)

 

Assuming that the datacenters have L3 connectivity, configure a vrrp instance as follows.

 

On Cluster 1 MC

 

vrrp 1

vlan <vlan used>

ip address 10.0.0.1

priority 110

preempt

authentication <choice of password>

description Preferred-Master

no shutdown

 

On cluster 2 Preferred MC

 

vrrp 1

vlan <vlan used>

ip address 10.0.0.2

priority 110

preempt

authentication <choice of password>

description Backup-Master

no shutdown

 

Now go to the AP system profile configured for the APs, can be viewed using the command "show ap system-profile"

 

open the ap system-profile using the command 

ap system-profile <name of the profile used>

 

Configure

lms-ip <cluster 1 MC>

Bckup-lms-ip <cluster 2 MC>

 

Save and deploy the changes.

 

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A_RAK is correct, that is the way of doing such a scenario. One thing to add. Instead of using a specific controller IP for LMS and Backup LMS I would use the Cluster VRRP for this entry. This makes sure, that the LMS or Backup LMS is available regardless of the status of a single controller. 

 

The AP will first connect to the LMS IP. This should be the cluster VIP of cluster 1. it will then learn all Controllers in cluster 1 and will create tunnels to the AAC and S-AAC in Cluster 1. The Ap will only failover to cluster 2 if all controllers in cluster 1 are down or not reachable. The AP will not create a standby tunnel to a controller in Cluster 2 before all Controllers in cluster 1 are down. 

 

Hope this gives more insights. 

Would you need to have all the VLANs configure on both clusters?

e.g. Cluster 1 allowed VLANs configured on Cluster 2, and vice versa?

Yes.  OR, you could create the WLANs (Virtual AP) with a VLAN name and then define a name to vlan number mapping on each cluster.

Do you also have to configure the same WLANs, AP Groups, Roles, and Profiles on the Cluster 2 controllers? 

If you enable pre-empt, does that take the head-ache out of moving the APs back to Cluster 1 after Cluster 1 comes back up?

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Jeremy Bradrick
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Original Message:
Sent: Sep 26, 2019 01:14 PM
From: Colin Joseph
Subject: AP Failover to another cluster POC

Yes.  OR, you could create the WLANs (Virtual AP) with a VLAN name and then define a name to vlan number mapping on each cluster.

Ideally, both clusters would be under the same folder, so they would have access to the same configuration.  If both clusters are not in the same folder/container, the APs will get the configuration for whatever ap-group they are in on the new cluster, which you would need to synchronize if you want the same behavior or you would have to manage two separate configurations.

Honestly, I have seen few people fail over devices to a second cluster as a best practice.  Having a cluster is its own redundancy (APs would exhaust connecting to all controllers in a cluster before failing over).  Failing over to a second cluster provides more redundancy, but more complexity.

Enabling pre-empt just makes things even more complicated, especially if you are not sure if only specific APs have failed over.  Long story short, your ultimate redundancy should just be a single cluster, unless you need site redundancy.  If you have a backup-lms pointing to a second cluster, that is where your APs will end up if they have failed to connect to all controllers in the first cluster.  Without pre-empt, that becomes your new APs cluster and they will "stick" to that cluster.  With pre-empt, things become more unpredictable as you will have to play the game of "where are all of my APs right now."

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Any opinions expressed here are solely my own and not necessarily that of Hewlett Packard Enterprise or Aruba Networks.
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Original Message:
Sent: Jan 07, 2022 08:18 PM
From: Jeremy Bradrick
Subject: AP Failover to another cluster POC

Do you also have to configure the same WLANs, AP Groups, Roles, and Profiles on the Cluster 2 controllers? 

If you enable pre-empt, does that take the head-ache out of moving the APs back to Cluster 1 after Cluster 1 comes back up?

------------------------------
Jeremy Bradrick

Original Message:
Sent: Sep 26, 2019 01:14 PM
From: Colin Joseph
Subject: AP Failover to another cluster POC

Yes.  OR, you could create the WLANs (Virtual AP) with a VLAN name and then define a name to vlan number mapping on each cluster.