If you’re planning on taking the Security+ exam, you should have a basic understanding of network design elements and components, including remote access methods. For example, can you answer this question?
Q. Management within your organization wants some users to be able to access internal network resources from remote locations. Which of the following is the BEST choice to meet this need?
A. WAF
B. VPN
C. IDS
D. IPS
More, do you know why the correct answer is correct and the incorrect answers are incorrect? The answer and explanation is available at the end of this post.
Remote access is the group of technologies that allow users to access an internal network from remote locations. Remote Access Service (RAS) provides access through dial-up or virtual private networks (VPNs). Several components come together to form a successful RAS solution. They include access methods such as through dial-up or a VPN, authentication methods, and network access control (NAC) technologies to inspect clients before granting them access to the network.
Telephony
Telephony is the use of telephone technologies to connect computers. Historically, telephony referred to the technical elements related to analog voice-based telephone systems. However, it has grown and now includes the technical elements supporting both analog and digital voice systems, along with fax and data transmissions. Although plain old telephone service (POTS) transmission wires still exist in many areas of the world, much of the underlying infrastructure supports broadband digital transmissions.
An extension of telephony is Internet telephony, also known as Voice over Internet Protocol (VoIP). VoIP phones allow users to make phone calls using a network connection with access to the Internet, rather than traditional phone systems.
Dial-Up RAS
Dial-up Remote Access Service (RAS) uses telephony technologies, including phones and modems. Both the client and server need access to phone lines, and each must have a modem. Dial-up RAS allows the client to have access to a remote network over traditional phone wires.
As a simple example, I was a traveling trainer for many years. While I was on the road, I could dial in to the RAS server using a laptop with a modem anytime I needed access to the company network. Once I connected, I could access resources on the network similar to how I could access the resources if I was at my desk at work—just not as quickly because I was using a 56K dial-up modem.
The client has a modem and access to a phone line and can dial directly into the RAS server. The RAS server also has a modem and access to a phone line. Once connected, the RAS server provides access to the internal network.
The primary protocol used for dial-up access is Point-to-Point Protocol (PPP). When it was developed, tapping phone lines was considered rare, so PPP didn’t include much security. However, PPP is often combined with other protocols to enhance security of the connection.
Long-distance phone costs can make dial-up cost prohibitive. VPNs provide better security than a dial-up solution and can reduce phone costs.
VPNs and VPN Concentrators
A virtual private network (VPN) allows a connection to a private network over a public network. The public network is most commonly the Internet, but it can also be a semiprivate leased line from a telecommunications company. Because the telecommunications company will often lease access to one physical line to several companies, the leased line is not truly private.
Access over a public network is a core security concern with VPNs. Different tunneling protocols encapsulate and encrypt the traffic to protect the data from unauthorized disclosure.
In large organizations, the VPN server is a VPN concentrator. A VPN concentrator includes all the services needed by a VPN server, including strong encryption and authentication techniques, and supports a large number of clients.
Q. Management within your organization wants some users to be able to access internal network resources from remote locations. Which of the following is the BEST choice to meet this need?
A. WAF
B. VPN
C. IDS
D. IPS
Answer is B. A virtual private network (VPN) provides access to a private network over a public network such as the Internet via remote locations and is the best choice.
A web application firewall (WAF) provides protection for a web application or a web server.
Intrusion detection systems (IDSs) and intrusion prevention systems (IPSs) protect networks, but do not control remote access.
You may like to view a blog post about Implementing VPNs.