What should be the destination address in coordinator, router and end devices in a mesh network?

I have one coordinator, two routers, and 3 end devices. How can I connect these devices in mesh network.
I need to communicate with End device - 1 through Router - 1. What should be the destination address in coordinator, router and end device?
And if my router - 1 fails, it should transmit through Router - 2.
Do I need to change the destination address in coordinator and end device in that case ?
How can i add both the routers to the coordinator?
I am using XCTU to configure the modules.

Coordinator DL: FFFF (Broadcast)
Router DL: 0
End Device: 0

You don’t mention the specifics radios you are using but modern modules are all AODV (Ad-hoc On-demand Distance Vector) enabled by default and are working in full mesh. If one router fails the packet get automatically routed through the second router in the range. AODV takes care of it and you can read more details how it works in the background, you don’t need to change the destination addresses manually to take care of it.

If your coordinator allows joining just setup additional routers with the same PAN ID and encryption settings to join the network.

Some additional advice from my side:

  1. Make sure your radios all operate in the same channel selection, have SC parameter at least 1FFF (or 7FFF) depending on your radios so that all radios can “see” each other.

  2. For the Routers in your network, I recommend turning on Network Watchdog (NW) it ensures that the link with the coordinator is kept active and if not, a reestablishment will occur (for example if you change Coordinator parameters and channel changes etc.)

  3. For end devices and routers, enable JV (channel verification), this ensures that whenever devices are powered on/off they will actually verify the channel that the coordinator is using.

Hope this helps. Cheers!