topic Inter-Subnet Roaming with no Layer3 Device? in Wireless

Inter-Subnet Roaming with no Layer3 Device?

Saman Shamim — Sun, 04 Jul 2021 04:54:51 GMT

Hi guys,

The following picture is from a network in a hotel:

- Cisco 3825 is managed by AT&T. No access to this.

- There is no Layer 3 device in this network.

- Access Gateway at 100.1 operates at Layer 2. It receives tagged traffic in order to keep track of billings and user accounts so we can't add a Router in internal network. (Please verify)

- WLC's Management Interface lives in VLAN 100 at 100.2 with Default Gateway of 100.1

- Another WLC with Management Interface different VLAN than above, will be connected to the "Core Switch" to have Mobility.

- With Mobility Groups, IP connectivity must exist between the management interfaces of all controllers.

- Routing between VLANs need a Layer 3 device.

Please share your thoughts about the following possible solutions to establish IP connectivity:

- Changing Management Interface VLAN on one side and match it with the other side to eliminate Routing Requirements and having Inter-Controller Roaming instead of Inter-Subnet Roaming. (Reboot required?)

- Adding a NAT device between two WLCs and use Proxy ARP. (Haven't done this before, does this work?)

- Do you have better solution(s) in mind?

Regards,

Saman Shamim

Inter-Subnet Roaming with no Layer3 Device?

weterry — Sun, 01 Apr 2012 05:19:07 GMT

Perhaps you can clarify a few things:

Why was the original plan for a 2nd WLC to have Management in a different VLAN?

Where does the client subnet fit into all of this? (and again, if your SolutionIP device is 100.1 [vlan 100] where does your 2nd WLC fit into this mix?)

What about your APs?

I'm still not fully grasping what the end goal is, but my suggestion would be to just stick APs and WLCs in the same vlan, and then just have your two different client vlans if you really needed it (assuming that is what this is about, wanting clients on wlc 1 in vlan 100, and cliens on wlc 2 in vlan XXX)....

Can you maybe provide a bigger picture (with how the 2nd WLC fits in).

Why can't you add a router in the network for the AP and WLCs? It sounds like your vlan 100 is strictly a client vlan that needs to go through the SolutionIP device for accounting, which would lead me to believe your WLC/AP connectivity is open for whatever you want to do with it.

Inter-Subnet Roaming with no Layer3 Device?

Leo Laohoo — Sun, 01 Apr 2012 05:34:04 GMT

Cisco 3825 is managed by AT&T. No access to this.

And you can't ask AT&T to route your inside network?

Re: Inter-Subnet Roaming with no Layer3 Device?

Saman Shamim — Sun, 01 Apr 2012 20:29:46 GMT

Thanks weterry. Hope the followings help:

Why was the original plan for a 2nd WLC to have Management in a different VLAN?

The 2nd WLC is in city's Convention Center and now an agreement has been signed off to implement wireless integration . The 2nd WLC has its own Gateway and Billing device and APs.

There is a fiber feed between the hotel and convention center.

I'm still not fully grasping what the end goal is

What we want is symmetric tunneling between WLCs so if a client roams from hotel to convention center, the traffic still should go through hotel's WLC and Gateway so the user don't have to pay again. Same thing for the roamed user from Convention Center to hotel.

Why can't you add a router in the network for the AP and WLCs?

Let me try to clarify things in my network in hotel:

- All APs are in the same vlan as the management interface (vlan 100).

- There are several dynamic interfaces, wireless vlans and AP groups on WLC.

- The original plan was to have these AP groups to differentiate billing rates and splash pages. For example, if you connect to guest AP group in building A, you see different welcome page and rates compared to connecting to meeting spaces AP group in building B.

- The SolutionIP device does the accounting based on received traffic tagged by the WLC. This is the reason that I did not use a router between SolutionIP and WLC. I know the router is not meant for layer 2 switching.

Thanks

Saman

***

And you can't ask AT&T to route your inside network?

No they don't 😐

Thanks leolaohoo

Inter-Subnet Roaming with no Layer3 Device?

Leo Laohoo — Sun, 01 Apr 2012 21:41:33 GMT

No they don't 😐

Then you definitely need to route your own.