One pain point of a quickly growing wireless network (especially when using 
public IPs) is to accommodate from growth.  Recently we went through an 
informal RFI process to select a new wireless vendor.  With Cisco we are now 
able to add IP address space to our wireless network by using AP Groups and 
assigning certain groups of APs to map our campus SSID(s) to certain VLANs.  
With this setup users in one building when connecting to the student SSID will 
get addresses from a different VLAN than students connecting to the same SSID 
in a different building. 
 
While this approach is far better than our previous setup it still requires 
some network changes when adding IP address space.  We can add another subnet 
when needed but we must then fiddle with AP groups to try to balance out or 
right-size each area of our wireless network.  It also leaves us vulnerable to 
unexpected client shifts.  If we have an AP Group area that usually has 60% of 
it's IP address space in use decide to host a conference and suddenly doubles 
the demand for IP address space we are left scrambling to accommodate for 
growth that may not be needed in the future.
 
With VLAN Pooling (I believe Aruba uses this) you can map an SSID to a VLAN 
Pool instead of a VLAN so when users connect to that SSID they are given an 
address from any subnet that has been assigned to that Pool.  >From my 
understanding this allows you to add IP address space simply by adding more 
subnets to the Pool.  It also eliminates the problem of large influxes of users 
who happen to come to a building that usually doesn't need a great deal of 
addresses.
 
This sounded very useful when the Aruba sales team was showing us their product 
but since I haven't actually tested or deployed a system with VLAN Pooling 
capabilities I can't speak to its effectiveness in practice.
 
Michael Simpson

>>> Mike King <[email protected]> 4/26/2010 8:24 AM >>>


On Fri, Apr 23, 2010 at 1:09 PM, Michael Simpson <[email protected]> 
wrote:


Though I wouldn't say it is a source of discontent, I would like to see VLAN 
Pooling added. 
Michael Simpson




Michael, What do you mean by VLAN Pooling? 
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