[c-nsp] Overlapping Subnet Issue - Gateway IP Resides in Vendor Assigned Public IP Range

[Sascha Pollok]

Spencer,

> You could have your isp assign a transit ip subnet for the link and then
> out your ips internal your border router. Another thing you could do static
> nats if the first option isn't available.
> On Jul 9, 2012 7:50 PM, "Spencer Barnes" <spencer at ceiva.com> wrote:
>
>> Hello,
>>
[...]
>> Our new ISP provided a gateway IP that is in the same subnet as the
>> external IPs they provided for use.  The range they provided (changed for
>> security) is 10.0.128.64/26.  They want us to assign 10.0.128.66 to our
>> WAN interface and point all outbound traffic to 10.0.128.65.
>>
>> The problem with this setup is I can't dedicate another interface for the
>> new external range because the subnets overlap.  I can change the g0/0
>> interface to 10.0.128.66 255.255.255.252 and assign the other interface
>> g0/1 10.0.128.96 255.255.255.224 but then I lose a bunch of external IPs.

As Chris has said. When you got a T3 or similar we are not talking about
some cheap residential thing. You ISP should provide a transit network!

-Sascha