Messer - 4. Network Security Flashcards
What is tamper detection?
A feature on devices such as computers and servers that notifies you if the case is opened. Should be enabled in BIOS settings. Allows systems to monitor themselves.
Foil asset tags are also available. If tag is removed, a message is left behind on the device.
TACACS stands for _________.
Terminal Access Controller Access-Control System
pronounced “tack acks”
What is TACACS?
A remote authentication protocol similar to RADIUS that uses the AAA framework (i.e. Authentication, Authorization, Accounting).
First used to control access to dial-up lines to ARPANET (ancient precursor to the Internet).
[See AAA and RADIUS in Infrastructure section]
What is XTACACS?
Extended TACACS
A proprietary Cisco-created version TACACS that provides additional support for accounting and auditing.
What is TACACS+?
Latest version of TACACS. (If you’re using TACACS today, this is probably what you’re using.) Often associated with Cisco, but available for many different OSes. Uses similar topology as RADIUS, but encrypts ALL information between client and server, whereas RADIUS only encrypts password.
SSO stands for ________.
Single Sign-On
What is Single Sign-On (SSO)?
An authentication scheme that allows a user to log in with a single ID and password to any of several related, yet independent, software systems. True single sign-on allows the user to log in once and access services without re-entering authentication factors.
(e.g. If you’re managing a group of switches and routers, you don’t have to log in to each separate device)
[See: Kerberos]
[Reminds me of PTSEM’s website. Had to log in separately for email, library, etc.]
What is Kerberos?
A network authentication protocol that offers single sign-on (SSO) functionality, which enables a user to log in to a system and access multiple resources without needing to repeatedly reenter username and password. Not only is this easier and less time-consuming for users, but makes network more secure because eliminates need to constantly send security credentials over a network.
It works by issuing cryptographic tickets when someone properly signs in, which can then be shown to other resources on the network. Uses mutual authentication (i.e. with both client and server) to protect against man-in-the-middle or replay attacks.
Used by Microsoft since Windows 2000, and used in Active Directory. But non-proprietary and cross-platform. However, does not work with every device. i.e. if your switches aren’t Kerberos-friendly, you may need to use a different authentication method.
What is Active Directory?
A Microsoft product used to centrally organize IT assets like users, computers, and printers. Allows IT admins to group people together and manage access to various devices, and provide single-on access to those devices (with the help of Kerberos). Integrates with most Microsoft Office and Server products. Uses Offers LDAP support to allow LDAP-based applications to work with an existing Active Directory environment.
LDAP stands for ________.
Lightweight Directory Access Protocol
What is Lightweight Directory Access Protocol (LDAP)?
A protocol for accessing and querying directory services systems. In the context of the N+, these directory services systems are most likely to be based on UNIX or Microsoft Active Directory. Although LDAP supports command-line queries executed directly against the directory database, most LDAP interactions are via utilities such as an authentication program (network logon) or locating a resource in the directory through a search utility.
LDAP is a derivative of the ______ protocol, also known as _______. The main advantage of LDAP is that it’s _______.
X.500
DAP
lightweight (duh)
What is local authentication? And what are its advantages and disadvantages?
Authentication done locally on a machine by an operating system using values / credentials stored within it. i.e. An alternative to using a centralized authentication server or service. Basically the opposite of technologies that use AAA Framework (e.g. Radius, TACACS, Kubernetes).
The advantage is that it works if there’s no Internet connectivity, or if the AAA server is unavailable. Functions as a backup that allows you to still access routers, switches, firewall, etc.
The downside, of course, is that by not using a centralized database, it’s difficult to scale. All changes must be made across individual devices.
PKI stands for ______.
Public Key Infrastructure
What is PKI?
A collection of software, standards, and policies combined to govern the issuance of digital certificates to protect sensitive data, provide unique digital identities for users, devices and applications and secure end-to-end communications. Uses a public and private cryptographic key pair obtained and shared through a trusted authority.
[Not sure how much we really need to know about PKI. It’s only listed in glossary of exam objectives. But I feel like it’s important to understand Certificates, which are definitely in objectives. Messer is pretty weak on this topic]
Explain how PKI’s encryption works.
PKI uses asymmetrical encryption, which basically just means you have two mathematically / algorithmically related keys.
If we use a public key to encrypt something, only the private key can decrypt it. This is great for secret correspondence. Just hand out the public key, and people can send us communication that only we can decrypt
But if I understand properly, we can also use the private key to encrypt something. And anyone can use the public key to decrypt it. Because we’re the only ones who can encrypt a message that the public key can decrypt, we’re able to prove our identity. So this would be helpful for digitally signing a document.
[Note: This is my own understanding based on looking at a few resources. Messer did not cover this at all]
What are four important components of a PKI?
Certificates
Certificate Authorities (CAs)
Certificate Templates
Certificate Revocation List (CRL)
What are certificates?
Electronic credentials that validate users, computers, or devices on the network. A digitally signed statement that associates the credentials of a public key to the identity of the person, device, or service that holds the corresponding private key.
ex. Certificates can be stored on laptop or thumb drive, then accessed during log-in process. They can also be on smart cards, which you can slide into a computer for access (along with PIN.)
What are Certificate Authorities (CAs)?
Issuers and managers of certificates. They validate the identity of a network device or user requesting data. CAs can be either independent third parties, known as public CAs, or they can be organizations running their own certificate-issuing server software, known as private CAs.
What are Certificate Templates?
Templates used to customize certificates issued by a certificate server. This customization includes a set of rules and settings created on the CA and used for incoming certificate requests.
[Don’t really get this one]
What is a Certificate revocation list (CRL)?
A list of certificates that were revoked before they reached the certificate expiration date. Certificates are often revoked because of security concerns, such as a compromised certificate.
What are the five possible factors in Multi-Factor Authentication? Give examples.
Something you know (e.g. password, pin, wipe pattern)
Something you have (e.g. smart card, dongle, USB token, phone)
Something you are (e.g. biometrics, fingerprint, voice, iris scan, gait)
Something you do (e.g. handwriting analysis, typing technique)
Geolocation (e.g. IP address, geolocation)
NAC stands for _________.
Network Access Control
Cisco calls their flavor Network Admission Control
What is Network Access Control (NAC)? Describe how it works.
A standardized approach for verifying that a node (i.e. device) meets certain minimum security criteria before it is allowed on a network. Certain advanced Cisco devices (e.g. switches and routers) use a feature called ‘posture assessment’ to do this. Includes checking for things like type and version of anti-malware, type and version of OS, level of QoS, presence of digital certificates, presence of keyloggers, whether machine is real or virtual, etc.
If everything checks out, host will be granted access to production network. Otherwise, host can be denied access, or quarantined on a non-production network.
The criteria to be assessed is gathered by a NAC agent, a piece of software that sits on the device being assessed.