Network administrators must be able to deny unwanted access to a network and allow authorized users to access necessary services. Security tools such as
passwords, callbackequipment, and physical security devices are helpful. They often lack the flexibility of basic traffic filters and the specific controls that most administrators prefer.
Listas deControl de Accesos
For example, a network administrator may want to allow users access to the Internet, but not permit external users Telnet access into the LAN.
Access - Lists
Routers provide thecapability to filter traffic, such as blocking Internet traffic, with access control lists (ACLs).
An ACL is a sequential list of permit or deny statements that apply to addresses or upper-layerprotocols. Standard and extended ACLs
as a way to control network traffic and explain how they are used as part of a security solution.
ACLs are lists of conditions used to test networktraffic that tries to travel across a router interface.
These lists tell the router what types of packets to accept or deny.
ACLs can be configured at the router to control access to a network orsubnet.
An ACL makes routing decisions based on
source address, destination address, protocols, and upper-layer port numbers.
ACLs must be defined on a per protocol, perdirection, or per port basis. To control traffic flow on an interface, an ACL must be defined for each protocol enabled on the interface. ACLs control traffic in one direction at a time on an interface.1
Inbound / Outbound
Two separate ACLs must be created to control inbound and outbound traffic. Every interface can have multiple protocols and directions defined.
TasksLimit network traffic and increase network performance. For example, ACLs that restrict video traffic could greatly reduce the network load and increase network performance. Provide traffic flow...