Sharing BT provided WAN between multiple private LANs

[james bennett]

Hi We have a large leased line coming into our office.  I've been asked to look into sharing the line with paying tenants in the office.  I've got some simple questions and some direction would be great.

What Cisco equipment would I require ?

How would I provision external public IPs

What routing protocols would be required?

I can think of a lot more questions but like I said just some general direction would be good

Thanks

[vmiller]

How may paying tenants are under consideration ?

Is there a logical way to define them (i.e. by floor.. business unit...)

Generally an ISP will provide you with one or two public IP's. 

depending on the answers to the first two questions, you may need more.

routing protocols - probably none. the ISP is the default route. you will need to consider

how to keep the tenants traffic seperated.

no sense looking at hardware until you get things scoped.

[james bennett]

Thanks for your feedback.  At the moment I still need to get it scoped but its looking like potentially I'll just be presenting a public IP address to the customer and I'm not sure that I want to get involved in the LAN side of things using VRFs and VLANs - assuming I understand what your saying...

The handoff by BT is the same, a public IP range into our firewall.

James

[james bennett]

Hi,

Been a long time but I have some more feedback now.

We are looking at 4 separate businesses in the 1 building, seperated by lock and key,  to share a 500Mbps leased line.  I'd like to be able to offer each business 50Mbps by presenting them a wall socket which will assign them a public IP address.  So for this I will need a mechanism where by I can present the public IP address.  Ideally if there requirement arose I would be able to add them extra blocks of public IPs as and when required.

Is there a way I can create VLANs with public IP addresses as I will need these(VLANS) to keep the traffic separate.  Alternatively, depending on which type of hardware I got for, I would like to just segregate traffic on the physical interface. 

My question is really how do I get the public IP address through from the ISP to the end user, would this be something I would do with Static NAT?  Would I have to waste a public IP address assigning it to the interface or could I use loopback maybe.

[Bilal Nawaz]

Hello James, You would need some sort of router for a start. Some of the things that might help you scale appropriately is, how much bandwidth on the leased line, how much throughput like pps, how many interfaces do you need.

You can separate these tenants traffic with VRF's and VLANs, if you only want to share internet then even one external IP may be enough. You don't need any routing protocols really, depends how the ISP do their handoff to customers.

[james bennett]

Hi,

Been a long time but I have some more feedback now.

We are looking at 4 separate businesses in the 1 building, seperated by lock and key,  to share a 500Mbps leased line.  I'd like to be able to offer each business 50Mbps by presenting them a wall socket which will assign them a public IP address.  So for this I will need a mechanism where by I can present the public IP address.  Ideally if there requirement arose I would be able to add them extra blocks of public IPs as and when required.

Is there a way I can create VLANs with public IP addresses as I will need these(VLANS) to keep the traffic separate.  Alternatively, depending on which type of hardware I got for, I would like to just segregate traffic on the physical interface. 

My question is really how do I get the public IP address through from the ISP to the end user, would this be something I would do with Static NAT?  Would I have to waste a public IP address assigning it to the interface or could I use loopback maybe.