AWS vpc access the Internet from public subnet

I configured public subnet on my VPC and add some Security Groups and NACL roles... I notice that when I set on NACL these roles in the inbound section :

100 SSH (22) TCP (6) 22 0.0.0.0/0 ALLOW 200 HTTP (80) TCP (6) 80 0.0.0.0/0 ALLOW 300 HTTPS (443) TCP (6) 4430.0.0.0/0 ALLOW

I didn't got access to the internet !!! :(

unless I added this role in the inbound section: 400 ALLTraffic ALL ALL 0.0.0.0/0 ALLOW

(after adding this role, I succeeded to get internet access by running "yum update" for example...)

It is really necessary or I configured somethings wrong ?

Thank for advanced, Roy