How to get the address of router from end device

Assume the connection :: (all devices are S2C)
:: one coordinator - one router - N end devices.

Would anyone tell how to get the router 64bit address from end device? I have a arduino attached to each end device and want to get it using arduino sketch.

What I did so far :: I issued ND command and tried to extract address in AT Command responce returned from router, but router didn’t return the responce. Is it a rule that router doesn’t respond to ND command?

Thanks for the help in advance,

No, routers will respond to an ATND command. You may just need to increase the wake time and decrease the Poll Rate command to get the response.