Assigned static IP from ISP on same subnet.

[dylan.murray]

I have searched the forums and found nothing that could help me here.

Client is using ADSL+ connection to the internet. I am trying to configure a 2911 router to make this WAN connection.

I am having IP address conflicts when configuring the interfaces because the ISP has provided an address block within the same subnet so when I try to add the second address it conflicts with the network  already provided. 

e.g 

fa0/0 - 10.10.10.1 255.255.255.0

fa0/1 - 10.10.10.2 255.255.255.0

The client is using the 2 highest addresses in the 16 address block and the ISP using the 2 lowest. 

What can I do to make this effective? I also need to implement EIGRP and a VPN to this project to work as a  hub and spoke branch to branch model for 4 remote sites (1 of them being the secondary HQ)

help would be appreciated

Thank you

[Jon Marshall]

So do you have two different internet connections coming to the router and how does this relate to the ISP ie. do you two connections from the same ISP etc.

Jon

[dylan.murray]

Hi Jon,

Yes there are 2 connections, set up for load balancing.

Thanks

Dylan

[Jon Marshall]

Well you can't assign two interfaces on the same router IPs from the same subnet unless you use VRFs and I doubt that is what you want.

Does the ISP know you only have one router and what about their end ie. if they have used two IPs do they have two routers ?

Jon

[dylan.murray]

The ISP does have 2 connections at their end. Does this mean I should have 2 routers, one for each public connection and configure them respectively?

I was under the impression that the data would have to travel through a single edge router to the outside. 

If I set it up with 2 routers could you tell me how I set up the load balancing as well as resilience so that if one WAN link were to fail it would pick up again within a certain amount of time?

Sorry if these questions seem dumb. I'm pretty new to this.

Thanks again

Dylan

[Jon Marshall]

It's difficult to say what is happening without more details because I have no idea how the ISP proposes to load balance.

With the IPs from the same subnet you would need two routers but you would also need to have the interfaces in the same vlan and with ADSL this isn't really applicable.

I would have thought the ISP would give you two separate blocks, one for each connection. The fact they haven't means I don't really know what they think is going to happen at your end.

I think you are going to need to talk to the ISP and ask them how they see this working.

Jon