For IP routes, it SHOULD contain a destination prefix in dotted
quad form optionally followed by a slash and a decimal length
specifier stating how many high order bits of the prefix to use.
That is followed by a space, a gateway address in dotted quad
form, a space, and one or more metrics separated by spaces. For
example, “192.168.1.0/24 192.168.1.1 1 2 -1 3 400”. The length
specifier may be omitted, in which case it defaults to 8 bits for
class A prefixes, 16 bits for class B prefixes, and 24 bits for
class C prefixes. For example, “192.168.1.0 192.168.1.1 1”.
Whenever the gateway address is specified as “0.0.0.0” the IP
address of the user SHOULD be used as the gateway address.
So without knowing the exact topology you’re trying to implement, here’s how you’d implement a route to 10.200.200.0/30 through 10.100.100.2: “10.200.200.0/30 10.100.100.2 1”. You can omit the Framed-IP-Address if it’s dynamic by using quad zeroes, which the NAS should substitute with the Framed-IP-Address: “10.200.200.0/30 0.0.0.0 1”