3.2 Flashcards
Secure infrastructures, intrusion prevention, network appliances, port security, firewall types, secure communication
3 ways to secure network connectivity
Application-level encryption
Network-level encryption (VPN, IPsec tunnels)
Secure the network cabling
A data security method that encrypts data as it passes through an application and across multiple layers, including disk, file, and database. It’s considered a secure approach to enterprise data protection because it protects data before it leaves an application, regardless of where it’s used, moved, or stored.
Application-level encryption
A configuration that allows data to continue to flow even after a system fails.
Fail-open
A configuration that prevents data from flowing (no communication/network connection) after a system fails.
Fail-closed
Devices that perform packet forwarding, monitoring, and examining services in a network. They are critical.
ex. Firewall, IDS, IPS, antimalware, routers, switches.
Inline devices
A type of monitoring that occurs when a monitoring tool is placed in the critical path of the network data. The traffic is monitored in real-time as it passes by.
Commonly used in IPS.
Active monitoring
AKA inline monitoring
A type of monitoring where a copy of the network traffic is examined using a tap or port monitor. The data cannot be blocked in real-time in this configuration.
Commonly used in IDS. (Even though it’s still using an IPS. This is because it can’t block traffic in real-time.)
Passive monitoring
AKA out-of-band monitoring
Why would an organization be uncomfortable with a real-time IPS?
It may cause some downtime to the network due to blocking legitimate traffic.
A network switch or router feature that copies network packets from one port to another for analysis. The copied traffic is then sent to a monitoring device, such as an intrusion detection system or network analyzer.
Port mirroring
SPAN stands for
Switched Port Analyzer
A dedicated port on a switch that takes a mirrored copy of network traffic from within the switch to be sent to a destination.
SPAN
A connection point in a network where real traffic is copied. The duplicate copies are then used for security analysis and monitoring.
Network TAP
A highly-secured device on the inside of a network, but it is accessible from the outside. It limits access only to individuals that are authorized.
It is used to administer critical networks remotely.
Jump server
A server that sits between the internal users and the internet. The internal devices connect to this server, and the server connects to the internet on the users’ behalf.
This allows the server to evaluate the packets, checking for malicious code, before giving it back to the user.
Proxy server
3 functions of a proxy server
Caching responses - saves time and bandwidth
URL filtering - limits what websites are accessible
Content scanning - blocks malicious code
2 types of proxy servers
Explicit
Transparent
A type of proxy server that must be configured in the application/client OS so that the app/OS knows to communicate with it.
Explicit proxy server
A type of proxy server that does not require any configuration for the application/client OS. It automatically makes request on a user’s behalf. The user has no idea that this proxy is in place.
Transparent proxy server
Most proxies in use are ____ proxies
Application-level
Meaning they understand the way applications work
True/False
Most application-level proxies only know how one application works (ex. HTTP)
False
While some proxies may only know one application, many of them are multipurpose proxies (ex. HTTP, HTTPS, FTP, etc.)
This proxy server sends out user requests to the internet and then examines the responses before passing them along back to the users. It sits inside the internal network with the user.
This server can also act as a caching server. When two requests are identical, the server simply sends out the cached response. This limits the load on the network.
Internal proxy
AKA forward proxy
This proxy server receives requests from the internet, examines them, passes them along to a web server, and then returns the response to the internet. It sits inside the internal network with the web server.
This server can also act as a caching server. When two requests have the same response, the server simply sends out the cached response. This limits the load on the web server.
Reverse proxy
A third-party, uncontrolled proxy server that is often used to circumvent security controls. It is available for anyone on the internet to use.
Instead of using the proxy inside your internal network, you connect directly to this proxy which does the work. This is a security risk because you don’t know who controls this device. The person controlling it could listen to your requests, add advertisements, or even inject malicious code into responses.
Open proxy
An invisible network device or service that breaks up traffic into smaller chunks for multiple servers to process.
This improves efficiency, provides fault tolerance, and dynamically changes how much traffic is assigned to what server in order to get the best performance.
Load balancer
The process of a dynamic routing protocol noticing and reacting to a topology change in order to shift to a stable state - for example, one of the devices failing. This is used in fault tolerance and load balancing.
Convergence
A load balancing configuration where all of the servers connected to the load balancer are all active and being used by the load balancer.
Active/active load balancing
A load balancing configuration where some servers are active and being used by the load balancer, while some other servers are on standby, waiting to be used when an active server fails.
Active/passive load balancing
5 additional functions of a load balancer
TCP offload
SSL offload
Caching
Prioritization - some apps/protocols get information faster
Content switching
A function of a load balancer that allows it to have a single connection to all servers, instead of having to repeatedly set up and tear down TCP sessions for each server. This improves response time.
TCP offload
A function of a load balancer that allows it to decrypt traffic before sending it to the servers, and then encrypting the traffic again to send a response. (ex. HTTPS to HTTP and vice versa)
This passes the traffic to the backend servers in cleartext.
SSL offload
AKA SSL termination