Controllerless Networks

Now IAP in a single cluster can support how many unit?

Please the Aruba Instant VRD for an answer to this question:

Cluster Design
By default, all Aruba IAPs on a Layer 2 domain form a cluster. No hard limit exists on the number of APs or clients that you can support on a single cluster. However, the maximum tested IAP cluster size is 128 IAPs in a cluster.
Guidelines for cluster and mobility design include the following guidelines:

• Aruba recommends that you use the validated cluster size of 128 APs and 2048 clients per cluster for your cluster design.
• To allow for some future growth, design a cluster at 80 to 90 % (about 110 APs) of the validated capacity.

Although the validated cluster size limit applies to a cluster, you can expand a deployment to more than 128 APs by deploying multiple clusters that have Layer 3 mobility enabled between them.

• If a deployment within a contiguous RF domain requires more than 110 APs, divide the deployment into multiple clusters and enable Layer 3 mobility between them.
• Layer 3 roaming has little to no impact on performance if you enable the Home Agent Load Balancing feature that is part of the Aruba Instant architecture. If you enable this feature, the VC assigns the home AP for roamed clients by using a round robin policy. With this policy, the load for the APs acting as home agents for roamed clients is uniformly distributed across all the IAPs in the cluster.

NOTE: Aruba recommends that you enable the Home Agent Load Balancing feature in deployments in which you expect a high volume of Layer 3 roaming between clusters.

If you need advice, please consult your Aruba Partner or Aruba Sales team. My personal experience is that the better control you have on the wired access switches (and follow the best-practices from the VRD, especially on broadcast control and separation of client traffic) the more APs you can put in one cluster with still proper performance. Starting from about 20-30 APs in a cluster, really make sure you follow the recommendations.

Hi Herman,

I have implemented several cluster of Instant, but they were small and with no special requirements.

1. Do you have experience with clusters of around 100 IAPs? This size of cluster has a good performance or is better two clusters of 50 IAPs?

2. If you have two cluster of Instant and you enable the Home Agent Load Balancing, is the roaming between clusters seamless with no disruption?

Regards,

Julián

Hi guys,

Anyone with experience with big clusters of IAPs?

Regards,

Julián

Yes sir, Which IAP Model you use to test.

Hello,

we will be deploy 120 AP-304 on warehouse. How many clusters do i need to deploy in instant mode or should I use a hardware controller?

100 access points is considered the limit for a cluster.  You should consider a controller if you would exceed that.

Thanck you for your answer but i do not understand why external controller is better than two or more instant clusters with L3 rouming?

Thanck you for your answer but i do not understand why external controller is better than two or more instant clusters with L3 roming?

I said, "you should consider".  I didn't say that you must.

A warehouse deployment is hard enough, if you use a controller, you can at least troubleshoot in a single interface.  If you have two clusters, you will have to troubleshoot devices over two interfaces.

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@cjoseph wrote:

100 access points is considered the limit for a cluster.  You should consider a controller if you would exceed that.

 

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Is that a new requirement? According to the Instant VRD and many other Aruba's documents (and also as Herman said at the beginning of this post), there is no hard limit of the number of IAPs for a cluster, although the number tested by Aruba is 128. Even if we take this number for the hard limit, the case of 100 IAPs is fine and there is still room for growing in the same cluster.

Regards,

Julián

The VRD says 128, but how many access points you can deploy is really dependent on the CPU of access point that is the VC (virtual controller) because it will be managing all the statistics for the cluster.  I was answering specifically to the question that @sotirr asked.  Having a cluster with 128 access points also mandates that there is little to no other wired devices on the same layer 2 management VLAN as the cluster.  If @sotirr  wants to skip past any of the possible issues, he should just deploy a controller.  Deploying a warehouse is labor intensive and @sotirr should get more Aruba advice specific to his/her deployment to determine which way to go.  I am answering based on the general information that @sotirr has given me.

Hi Colin,

Thanks for aswering. Two doubts about this:

1. I didn't realize the AP in question is an AP-304, which is a small AP in terms of CPU, etc. So, what model of AP have to be considered to form a cluster of around 128 IAPs?
2. You said "Having a cluster with 128 access points also mandates that there is little to no other wired devices on the same layer 2 management VLAN as the cluster." If you have a management VLAN of mask /24 for example, you can have till 254 hosts. Can't you have 128 IAPs and 126 wired devices on the same management VLAN?

Regards,

Julián