Index by OID Value

[arsenic]

How can I index network interfaces by an OID value instead of OID index? The OID indices in my device change as interfaces are added and removed.

Lets say the router returns the following interfaces:

o.i.d.0.0 = 0
o.i.d.1.0 = interface0

o.i.d.0.1 = 1
o.i.d.1.1 = interface1


If I add a new interface, like, interface 0.1, the OIDs shift by one, resulting in:

o.i.d.0.0 = 0
o.i.d.1.0 = interface0

o.i.d.0.1 = 1
o.i.d.1.1 = interface0.1

o.i.d.0.2 = 2
o.i.d.1.2 = interface2


The data source and graphs of interface2 will become interface0.1's, which is wrong. They should remain with interface2. How can I prevent this?