interfaces in same IP range

I have a PIX 515 I am trying to configure on a network.
This firewall was running 5.1 and was recently upgraded to 6.3.5.
I have applied a new activation key from Cisco.
The old config had the inside IP's:
route 1
static (inside,outside) netmask 0 0

I have the firewall setup in a lab now.  I am trying to change the outside to and inside to my dsl router is
I can set the outside ip but when I set the inside i get sorry not allowed to enter IP address on same network as interface 0.

However, if I use outside inside it takes it.
I have tried and as outside but it would not take that in a 255.0 subnet.

Is this new with 6.3.5?
Heath CalhounAsked:
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SteveH_UKConnect With a Mentor Commented:
The IP addresses are part of the standard class-C private networking range which specifies that 192.168.x.y addresses form a set of 256 distinct private networks each with a subnet mask  This means that each value of 'x' represents a different network.

The problem you are getting is that and are addresses in the same subnet.  Since you do not route between IP addresses in the same subnet, your router is complaining.  Instead, you need to use different subnets on your internal and external interfaces.  The easiest solution may be to change the 'x' on your internal side, so that you use as outside and as inside.

Here's a technical introduction to IP addressing and routing:
Heath CalhounAuthor Commented:
After falling asleep woke up remembering the subnet calculator i looked at.  .65 and .130 were outside the .66-.126 range.

Glad you're sorted :)
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