Intorduction of ACL(Access Control List)

ACL plays very important role to provide network security by blocking network

traffic against the set of rules defined by network administrator. In this article

we will learn about the concept of acl.

What is ACL

Access control list(ACL) is the set of rules that control to permit or deny

flow of data from the network layer based on the rules which is defined by

network administrator. ACL enhance the network security. defined on router and as well as firewall. ACL filter the

traffic as per security policy defined by network admin.

ACL should be placed edge

location of the network.

ACL is configured based on three rules:

· 1acl per protocol:We can control the every protocols which is configured on router as well as firewall by acl.

· 1acl per direction:There is two directions one is incoming and other is outgoing which is controlled by acl as per defined rule by network admin.

· · 1 acl per interface:we can control the interface traffic using acl which is defined by network admin.

What is packet filter

Packet filter is the method to check the incoming and the outgoing packet in the

network by the set of rules to understand whether these packets are forwarded or

dropped. It is defined on router as well as firewall.

Access Control List

Types of ACLS

There are two types of acls one is standard acl and other is extended acl.

Standard ACL: In this acl network admin permits or deny the network traffic using

source address.This acl will be set closest to the destination.Range of this acl is

<0-99>.

Extended ACL: In this acl network admin permits or deny the network traffic using

several criteria which includes source and destination ip address,protocol and source and destination port no.This acl should be placed closest to the source. Range of this acl is <100-199>.

Intorduction of ACL(Access Control List)