john_westlund's profile

26 Messages

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470 Points

Tue, Nov 19, 2019 4:12 PM

VLAN Pooling Behavior

I have 3 vlan pools created.  Two of them contain 2 vlans and the other contains 4 vlans.  The 2 vlan pools work like I expect with it placing clients in each vlan.  The 4 vlan pool is only placing clients into the first two vlans.  I am only in a testing phase right now and when I look in the first two vlans I'm typically seeing 10-15 addresses used.  Will the SZ not dip into the other vlans until It's getting closer to capacity on the first two?

Responses

Employee

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30 Messages

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670 Points

2 y ago

Hi John,

Ruckus VLAN pooling uses the MAC address of the client device against a fixed algorithm.

This ensures that the client device will be assigned to the same VLAN from any AP in a given network which is essential for seamless roaming.
Using this method, it is not possible to guarantee an exactly even balance between the VLAN pools as would be when using 'round robin' or 'assign least used VLAN' pooling methods. Both of these methods would introduce roaming issues as a client may be assigned a different VLAN on an AP they have roamed to leaving the device without valid IP information until it is disconnected and reconnected.
 
With this in mind, it is strongly advised to create IP address pools within each VLAN that are considerably bigger than the even share that would be expected. Best practice dictates that each pool should have enough IP address to handle ALL of the devices in each pool to guarantee that any single pool cannot be exhausted.
 
The VLAN pool assigned is based on the last octet of the client device's MAC address. This value is divided by the number of available pools. The remainder of this calculation decides which pool the device will be assigned to.

Regards,

Phil.

1 Message

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62 Points

does this mean that when I have 7 VLAN of 250 hosts each, if these VLANs are members of the same pool, I can get an IP address from the DHCP server in any VLAN of the pool, even if the first VLAN is not full yet? I mean, if I have 2 phones and they connect to a WLAN which is attached to the VLAN pool, one can get an IP from VLAN 1 and the other from VLAN 2?

15 Messages

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156 Points

Yes, as Phil mentioned, VLAN pooling was based off the client's mac address and a hash was done in order to determine which VLAN the user will end up in. So you may fill up a vlan or not as it depends on the mac address.

In SmartZone 6.0, this has been enhanced to distribute it more evenly. 

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