Heads Up :
The post you are writing will appear in a public forum. Please ensure all content is appropriate for public consumption. Review the employee guidelines for the community here.
We have tried this with no joy so far, I suspect the outside mask will need to change to allow for both subnets IE class A 0r B in this case even though the ISP subnets are both /29, this may fool the pix and router to see each other.