Standard Named Access Control lists are the list of conditions that are used in the network to avoid traffic. The conditions are listed in numbers or names. And these conditions are used to avoid traffic on routes. Through these conditions, we can avoid or filter traffic.
When an interface receives a packet following procedures happens:
- The first router grasps the destination address of the packet.
- Secondly, the routing table contains the address and these are used to check the address of the destination.
- Thirdly, the interface forward the address only the above comparisons are get matched.
- The match is not found the packet will get discarded.
There are three different types of ACLs, they are:
- Standard ACLs
- Extended ACLs
- Named ACLs
To remove unwanted traffics from the network standard access control list were used. In the network traffics is passing through the router by following a set of procedures that are defined by the standard access control list. The routers only allow the packets which have permissions to pass. Other packets that have no permission to enter are destroyed from the way.
Two ways are used to describe the standard access control lists, they are mentioned below:
- Classic numbered method
- Modern numbered method
- Modern named method
Standard Access Control List is a type of access control list used to filter the traffic and is not commonly used one is an odd one. The traffics is controlled along with the data contained with them. The traffics in the networks is controlled based on the source IP addresses. By using the “access-list” IOS command standard access list can be created.
Using the name or the number all the access lists are defined and are used. It is easy to recognize and use named access rather than numbered access lists. In an extended control list, they can differentiate the IP traffic, unlike the Standard Access Control List.
In Extended ACL they use both source and destination address and the port number to differentiate the IP traffic. Extended control list filter packets which are near to source address.
Create Standard Named Access Control List (ACL) using “access-list” IOS command
An IOS command named access-list is used to create the standard named access control lists. The global configuration command used in this command is Router03. Standard named access control lists can filter all traffic to the destination network if the “no permit” statement is not written at the end of the statement. No command is used to remove the access control lists.
We use an IOS command named “access-group” for the configuration of the standard access control list. The access list can be used with the interface by using this command. To specify the direction of filtration the in/out keyword is used.
When the traffic arrives at the interface or the router filtrations need to take place which is specified in the keyword. When the traffic leaves from the router or the interface filtration occur and these are specified in the out keyword. To remove or delete the standard access control lists from the interface the command used is “no”.
Must read these articles.
- Where should the Standard Access Control list be placed?
- Where should the Extended Access Control list be placed?
Download How to Create and Configure Standard Named Access Control list in pdf- Click here