In some cases you can do this using the broadcast address, which is different then the listen and rpc address. But if nothing is route-able ie NAT I do not think it is possible.

On Sun, Mar 10, 2013 at 10:05 AM, Илья Шипицин <chipitsine@gmail.com> wrote:
Hello!

Is it possible to run cluster in 2 datacenters which are not routable?
Each datacenter is running its own lan prefixes, however lan are not routable across datacenters.

Cheers,
Ilya Shipitsin