Route Problem

I have a problem with Routers , i cant to understand why , one router sometime i cant to access
when i ping from my PC one router before that router that i have problem respond with Destination Unreachable and when i access in that router and ping that router IP reply very good
the problem is that sometime i can access in that router , sometime no
?

Could you be more specific and provide more details?

I have attached a Pic , and when i ping from my PC the Router 4 and Router 5 i have an answer from 10.2.15.1 which say the destination host unreachable
and when i open the Router 10.2.15.1 i see route in this Router toward Router 4 and Router 5
and sometime i can ping the Router 4 and Router 5 but sometime i cant ping , even them are powered on and exist Route
i cant to understand why ?
Example.JPG

Do you have a route to the 192.168.200.0/24 network in router3, router4 and router5?
Or do you have a masquerade somewhere in there?

edit: Does this network connect to the internet? If so, which router?

yes the router 2 connect with another Router which is connected to internet , and i have natted the network 192.168.200.0 in router1 with one ip of the router 1 which is connect with other routers
so in other routers its a route toward that ip which masquerade the network 192.168.200.0
!

When you say router2 connects to the internet through another router, you mean a router besides router3?

I suspect a NAT or route in router2 may be causing the problem. It might help if you posted “/ip route” and “/ip firewall nat” from router2.