flex connect

[bluesea2010]

Hi,

Hi ,
Acces points are running in flexconnect mode . Access Layer is layer 3
single SSID , Dynamically allowing vlans based on group membership .

group 1 -vlan 100
group 2 - vlan 200
VLAN 100 and 200 on every floor.


Each vlan has a total of 500 to 1000 users on all floors.

I want to divide 10.0.0.0/16 Between each floor

VLAN 100, for instance.
10.0. 0.0/23 -- ground.
10.0. 2.0/23 -- first.
10.0. 4.0/23 --second.
10.0. 6.0/23 -- third

Since layer 3's access layer is where all of the gateways are located, is it ok /23 in each floor for all vlan ?

Given that layer 3's access layer is where all of the gateways are located on edge switches, is it acceptable to have /23 in each floor for all vlans.
Any pros and cons

Thanks

.

[Rich R]

Well /23 gives you about 500 IPs - so question is how many unique users per VLAN per floor.
Also take into account the amount of user churn (users leaving and arriving) and how long your DHCP lease time is.
Eg. if you have 500 possible unique users each with at least 2 devices each then you need at least 1000 IPs so you'd need to use at least /22 and maybe more to make sure you have plenty of spare capacity for proliferation of devices.

[bluesea2010]

Hi,

Layer 3 roaming Requires, Access layer is layer 3 .
So the user moving from floor to floor the the first ip address will be retained.

Let's assume half of the users are moving from the first floor (10.0.0.0/22) to ground floor (10.0.4.0/22) ,

does it impact the ip address space in the ground floor

Thanks

 

[Arshad Safrulla]

/23 subnets must be decided based on your network and clients. You might have to fine tune the dhcp lease timers according to what you see on your network and how users roam between floors. Its very difficult to answer this without much insight in to the design as whole

Running Flex connect APs on Layer 3 routed access switches is going to be challenging. You will have a nightmare troubleshooting the issues. For example if a user moves from ground floor to first floor user may need to acquire new IP address if the subnet is different for the new VLAN. And also it is perfectly possible while the user is in ground floor he will connect to first floor (if the coverage is leaking) and then when roaming to ground floor AP disconnections may happen. 

For any Layer 3 routed access network recommended setup would be local mode APs where the traffic is tunneled to the WLC.

[bluesea2010]

Hi @Arshad Safrulla 

Hi,

1.if a user moves from ground floor to first floor user may need to acquire new IP address if the subnet is different for the new VLAN

As I Understand when we enable layer 3 roaming ,the client can continue using its current IP address.

2. For any Layer 3 routed access network recommended setup would be local mode APs where the traffic is tunneled to the WLC.

It means I have to create layer 2 (trunk) connection to  wlc from the core switch

And the ssid vlans gateways (svi) will be on core switch

Correct me if I am wrong

Thanks