I have Two Networks in connection as following,

First Network -------> switch --------> router -------> Second Network

First network's ip is 10.100.A.A , it's subnet mask is

Switch's ip is 10.100.B.B , it's subnet is also

router's ip is 10.100.C.C , it's subnet is also

Second network's ip is 10.10.D.D , it's subnet is also

The problem is as following

1. I can ping from First network to switch but cannot thence to router and also to second network
2. I can ping from switch to router but cannot thence to second network
3. I can ping from second network to router but cannot thence to switch and also first network
4. I can ping from router to both switch and first network

Medias are as follow:

Fibre optics between switch and router
ethernet between switch and first network
ethernet between router and second network

Please advice me for the above,
Thank in advance.

I think the IP addressing scheme is wrong. You should have the first network and the switch(not required to have an IP address except for management purpose) and the interface of the router in same IP address range. Let's say 10.100.100.A with a mask of and apply same concept for the second network