Authentication Summary

Question 1

802.1x

Answer 1

IEEE standard for Port-based Network Access Control (PNAC). Its a data link layer authentication technology used to connect devices to a wired or wireless LAN. It defines the EAP protocol.

Question 2

LDAP

Answer 2

Application layer protocol for accessing and modifying directory services data. Microsoft Active Directory uses it.

Question 3

Kerberos

Answer 3

Authentication protocol used in Windows to identify clients to a server using mutual authentication (tickets).

Question 4

Remote Access Services (RAS)

Answer 4

Service that enables dial-up and VPN connections to occur from remote clients.

Question 5

Challenge Handshake Protocol (CHAP)

Answer 5

Authentication scheme used in dial up connections. Almost completely phased out.

Question 6

RADIUS

Answer 6

Centralized administration system used for dial-up, VPN, and wireless authentication. Uses port 1812/1813 (UDP) or 1645/1646 (UDP). Uses 802.1x and EAP.

Question 7

TACAS+

Answer 7

Cisco’s version of RADIUS. Uses port 49 (TCP)