Ip address overlap error ?

Tokyo(config)#int e0

Tokyo(config-if)#ip add 192.168.1.129 255.255.255.0

Tokyo(config)#no shutdown

Tokyo(config)#int s0

Tokyo(config-if)#ip add 192.168.1.1 255.255.255.252

% 192.168.1.0 overlaps with Ethernet0

I cant see the error here, Is there an overlap because both will have a wire address of 192.168.1.0 ?

The network address of 192.168.1.129 255.255.255.0 is 192.168.1.0 which is the same as that for the serial interface. You could fix it by allocating the ethernet interface 192.168.1.129 255.255.255.192. The latter has a network address of 192.168.1.128.