2.1 Install and configure network components Flashcards
Firewall
A firewall is a network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules
Types of implementations:
1) Firewalls that protect a whole network
2) Firewalls that protect a single host.
3) Border firewalls, filter traffic between trusted local network and untrusted external networks.
4) Internal firewalls, such as DMZ config’s can be placed anywhere within the network, either inline or as host firewalls, to filter traffic flows between different security zones.
ACL
(Access Control List) Specifies which subjects (user accounts, host IP addresses) are allowed or denied access and privileges given over the object.
Application-based firewall vs. network-based firewall
Application-based firewalls: run as software on any type of computing host.
Network-based: hardware firewall that performs function of firewall only.
Stateful vs. stateless
Stateless: a type of firewall that does not preserve information about the connection between two hosts or previous packets. ex. packet-filtering firewall.
Stateful: a type of firewall that stores information about hosts in a dynamically updated stable state .
Implicit deny
A basic principle of security stating that unless something has explicitly been granted access, it should be denied access.
VPN concentrator
A VPN-enabled router. Helps manage multiple VPN gateways remotely. It is a server-side feature.
Remote access vs. site-to-site
Remote access: clients temporarily connect to a VPN gateway from a local network.
Site-to-site: two or more local networks permanently connected, each of which runs a VPN gateway. ex. branch office connected to headquarters
IPSec
Internet Protocol Security: a set of standards you can use to secure data as it travels across a network or the internet.
Tunnel mode
1/2 IPSec mode; the IP header for each packet is not encrypted, just the data (payload). This mode would be used to secure communications on a private network.
Transport mode
2/2 IPSec mode; the whole IP packet (header and payload) is encrypted and a new IP header added. This mode is used for communications across an unsecure network. This is also referred to as a router implementation.
AH
Authentication Header; AN IPsec PROTOCOL that provides authentication for the origin of transmitted data as well as integrity and protection against replay attacks.
ESP
Encapsulation Security PAYLOAD; an IPSec protocol that provides authentication AND confidentiality by encrypting the packets.
Split tunnel vs full tunnel
The two ways of managing a connection between a client and a VPN.
Split tunnel: the client accesses the Internet directly using its “native” IP configuration and DNS servers.
Full tunnel: Internet access is mediated by the corporate network, which will alter the client’s IP address and DNS servers and may use a proxy.
TLS
Transport Layer Security VPN; commonly referred to a SSL VPN, is a client-to-server connection that authenticates the client which creates an encrypted tunnel for the user to submit authentication credentials.
Always-on VPN
A version of VPN where the computer establishes the VPN whenever the Internet connection over a trusted network is detected.
NIPS/NIDS
Network-based intrusion Prevention system: an inline security device that montors suspicious network and/or system traffic and reacts in real time to block it.
Network intrusion Detection system: a packet sniffer with an analysis engine to identify malicious traffic and a console to allow configuration of the system. Provides passive detection. Identifies and logs hosts and applications, and detects attack signatures, password guessing attempts, port scans, worms, backdoor applications, malformed packets or sessions etc.
Signature-based
Also referred to as pattern-matching, means that the engine/anti-virus is loaded with a database of attack patterns or signatures. If traffic matches a pattern, then the engine generates an incident.
Heuristic/behavioral Detection
Also referred to as profile-based detection, means that the engine is trained to recognize baseline “normal” traffic or events. Anything that deviates from this baseline generates an incident. Helps detect ‘zero day’ attacks. The engine generates a statistical model of what the baseline looks like, using heuristics.
Anomaly (logs)
Looking for irregularities in the use of protocols.
Inline vs. passive (protection)
Inline: protects the whole network, provides active response to any network threats
Passive detection: log intrusion incidents and to display an alert to mgmt. interface/email admin account.
In-band vs. out-of-band
In-band: the sensor uses the same network as the link being monitored
Out-of-band: establishes separate cabling infrastructure or same cabling but separate VLAN.
Rules
plug-ins, feeds
Analytics (logs)
The process of reviewing the events and incidents that trigger IDS/IPS
Router firewall
A router firewall has firewall functionality built into the router firmware.
Anti-spoofing
IP spoofing disguises the identity of the attacker’s host machine. Anti-spoofing requires authenticated IPSec tunnels to critical services
Switch
Switch ports are used to physically segment or segregate hosts.