Anyone please kindly to show me how to setup internet in Mikrotik with standard configuration 
Ex: IP public : 110.203.123.29
Gateway : 110.203.123.1
DNS : 119.82.248.67.
Thanks for advanced
This is all covered in the manual.
Assign IP address: http://wiki.mikrotik.com/wiki/Manual:IP/Address
Assign a default route:http://wiki.mikrotik.com/wiki/Manual:IP/Route#Default_route
In your example:
/ip route add dst-address=0.0.0.0/0 gateway=110.203.123.1
thanks for your advices.
Be aware that if you do not set up a firewall too, your system will be completely open to the outside world.
The minimum firewall would be something like this. Open new terminal in winbox and paste code. Replace 192.168.0.0 with the correct network IP for your LAN.
/ip firewall filter
add action=drop chain=forward comment=“” connection-state=invalid disabled=no
add action=accept chain=forward comment=“” connection-state=established disabled=no
add action=accept chain=forward comment=“” connection-state=related disabled=no
add action=accept chain=forward comment=“” connection-state=new disabled=no src-address=192.168.0.0/24
add action=drop chain=forward comment=“” disabled=no dst-address=192.168.0.0/24 src-address=192.168.0.0/24
add action=accept chain=input comment=“” disabled=no dst-port=22 protocol=tcp src-address=192.168.0.0/24
add action=log chain=input comment=“” disabled=no dst-port=22 log-prefix=“” protocol=tcp
add action=drop chain=input comment=“” disabled=no dst-port=22 protocol=tcp
See enclosed PDF reg setting up NAT and it gives a good understanding of the initial setup.
rosmE.pdf (448 KB)