EXAMINING VPNs And QoS

Question 1

What are VPNs?

Answer 1

A secure, encrypted connection over public networks, such as the Internet

VPNs provide secure remote access or connect multiple sites.

Question 2

What are the different types of VPNs?

Answer 2

Two main types:
* Site-to-Site
* Remote Access VPNs

Site-to-Site connects entire networks, often for remote offices, while Remote Access allows individual users to connect from a remote location.

Question 3

What is the purpose of Site-to-Site VPNs?

Answer 3

To connect entire networks to each other, facilitating secure communication between different sites over the internet

Often employed for connecting remote offices to a company’s main network.

Question 4

What is the primary use of Remote Access VPNs?

Answer 4

To allow individual users to connect to a private network from a remote location

Commonly utilized for telecommuting or accessing corporate resources remotely.

Question 5

What is PPTP?

Answer 5

Point-to-Point Tunneling Protocol (PPTP) is an older VPN protocol that is easy to set up but has security vulnerabilities. It uses TCP port 1723 for tunnel maintenance and IP protocol 47 for GRE (Generic Routing Encapsulation).

Question 6

What is L2TP?

Answer 6

Layer 2 Tunneling Protocol (L2TP) is a combination of PPTP (Microsoft) and L2F (Cisco). It is commonly used with IPsec for encryption and uses UDP ports 1701 for L2TP traffic, 500 and 4500 for IPsec.

Question 7

What is IKEv2?

Answer 7

Internet Key Exchange version 2 (IKEv2) is part of the IPsec suite used for establishing and managing security associations. It uses UDP ports 500 for the initial key exchange and 4500 for NAT traversal.

Question 8

What is MPPE?

Answer 8

Microsoft Point-to-Point Encryption (MPPE) works with PPTP for encrypting data on Microsoft VPN networks.

Question 9

What is SSTP?

Answer 9

Secure Socket Tunneling Protocol (SSTP) is developed by Microsoft and uses SSL/TLS for encryption. It offers security and the ability to bypass most firewalls, using TCP port 443, the same port used for HTTPS traffic.

Question 10

What is IPSec?

Answer 10

Internet Protocol Security (IPSec) is a suite of protocols for securing internet protocol communications by authenticating and encrypting each IP packet.

Question 11

What is QoS?

Answer 11

Quality of Service (QoS) is a set of technologies used to manage network traffic and prioritize different types of data.

Question 12

What is the purpose of QoS?

Answer 12

Ensures predictable network behavior and performance, particularly for time-sensitive applications like VoIP and video conferencing.

Aims for reliable and consistent data packet delivery, reducing latency, jitter, and packet loss.

Question 13

Where do we see QoS implemented or used?

Answer 13

In network devices such as routers and switches.

Question 14

What do QoS functions perform?

Answer 14

Implements traffic policies - shaping and policing, bandwidth allocation, and queuing to prevent traffic congestion.

Question 15

How can routers determine priority?

Answer 15

Using the Terms of Service (ToS) Field in IPv4, which is an 8-bit field in the IPv4 header for indicating packet priority.

Includes bits for precedence, delay, throughput, and reliability.

Question 16

What is the Differential Service Code Point (DSCP)?

Answer 16

Occupies the first 6 bits of the ToS field in IPv4/Traffic Class field in IPv6, allowing for 64 different classes of service and providing granular packet classification.

Question 17

How can switches determine priority?

Answer 17

Using VLAN tagging (IEEE 802.1q), which includes priority bits in the VLAN tag, allowing QoS policies based on VLAN ID.

Question 18

What is Priority level (802.1p)?

Answer 18

IEEE 802.1p (Priority Tagging) adds a 3-bit class of service (CoS) priority field in the Ethernet frame, defining 8 priority levels used by switches for traffic prioritization and congestion management.