According to an example, security and access control may include receiving traffic that is related to an application tier of a plurality of application tiers, and that is to be routed to another application tier or within the application tier. The attributes of the traffic related to the application tier may be analyzed, and based on the analysis, an application related to the traffic and a type of the traffic may be determined. The type of the traffic may be compared to a policy related to the application to determine whether the traffic is valid traffic or invalid traffic. Based on a determination that the traffic is valid traffic, the valid traffic may be forwarded to an intended destination. Further, based on a determination that the traffic is invalid traffic, the invalid traffic may be forwarded to a predetermined destination or blocked.