Category Archives: ACLs

What is VPN? Features of a Secure VPN

What are Features of a Secure VPN? VPNs use advanced encryption techniques and tunneling to permit organizations to establish secure, end-to-end, private network connections over the Internet. The basis of a secure VPN is data confidentiality, data integrity, and authentication: i  .   Data confidentiality – The common network security concern is protecting data from hackers. Data confidentiality aims at… Read More »

How to Apply ACLs on Interfaces Examples

On this page we describe how IP access control lists (ACLs) can filter network traffic. It also contains brief descriptions of the IP ACL types, feature availability, and an example of use in a network. We going to Configure standard access-list according to a given set of conditions. Instructions: 1. Hosts on Router R3 should not be able to access… Read More »

What is Extended ACLs? Explained with Examples

Extended Access Control Lists. Like Standard ACLs, extended ACLs check the source packet addresses, destination address, protocols and port numbers. Extended Access Control Lists (ACLs) provide a greater range of control and, therefore, an addition to your security solution. Extended ACLs provides for more precise traffic-filtering control, you can use extended ACLs numbered 100 to 199 and 2000… Read More »

How To Configure Extended ACLs on a Cisco Router

Extended ACLs Configuration Example. The practical steps for configuring extended ACLs are the same as for Standard ACLs, you first create the extended ACL and then activate it on an interface. The figure below shows an example of how you might create an extended ACL specific to your network needs. In this example, the network administrator needs to restrict… Read More »

What is Complex ACLs? Explained with Examples

Complex Access Control Lists. When there is additional functionality on Standard and Extended ACLs, we term it to be complex or large ACLs. There are three categories of Complex or large ACLs: i.    Dynamic or Lock-and-key ACLs ii.   Reflexive ACLs iii.  Time-based ACLs What are Dynamic or Lock-and-key ACLs? Dynamic or Lock-and-key ACLs is an IP traffic filtering feature. This type of access control… Read More »

What are Common Network Security Threats?

Three common factors emerges when dealing with network security, these are vulnerability, threat, and attack. Vulnerabilities An experienced hacker knows that every network or device has a certain degree of vulnerability or weakness, and they take advantages of each security weakness or loophole to exploit the network.  A  Computer network hackers work round the clock in search of unsecured… Read More »

Configuring Extended ACLs Examples

Lets look at how to configure an extended access list to enable users on a network  browse secure and insecure websites. Firstly,  consider if the traffic you want to filter is going in or out. Access to websites on the Internet is traffic going out, receiving e-mails from the Internet is traffic coming in. Applying extended ACL on… Read More »

What is Denial of Service? Explained with Examples

DoS attack prevents authorized users from using network services by consuming system resources. Most times DoS attack is regarded as trivial but in a sense it is a consequentially threat. DoS can cause potential damage to networks. Not only are they easy to execute, but its among the most difficult to eliminate. DoS attacks deserve special attention from… Read More »

What is Switchport ACLs?

How to Configure Switchport   The Switchport ACL (PACL) feature provides the ability to perform access control on specific Layer 2 ports. ACLs can also be used to control traffic on VLANs. Switch port ACLs can only be applied to Layer 2 interfaces in the inbound direction, and this controls traffic via IP access Lists. Switch port ACL application… Read More »

What is PPP? How to Configure PPP on Cisco Router Example

You can configure point-to-point encapsulation, software compression, link quality monitoring, load balancing across links (multilinks) on R1, R2 and R3 serial interface below. Before you actually configure PPP on a serial interface, we will look at the commands and the syntax of these commands as shown below. This series of examples shows you how to configure PPP and some of the options. 1: How to enable PPP on… Read More »