Lantronix XPort AR - Manual (Page 67)

9: Services Settings
XPort AR User Guide 67
1. Click DNS on the Main Menu. Figure 9-1 shows the page that displays.
Figure 9-1 DNS Status and Cache Web Page
PPP Configuration
The Point-to-Point Protocol (PPP) establishes a direct connection between two nodes. It defines a
method for data link connectivity between devices using physical layers (such as serial lines). The
XPort AR supports two types of PPP authentication: Password Authentication Protocol (PAP) and
Challenge Handshake Authentication Protocol (CHAP). Both of these authentication methods
require the configuration of a username and password.
PAP authentication offers a straightforward method for the peer to determine its identity. Upon the
link establishment, the user ID and password are repeatedly sent to the authenticator until it is
acknowledged or the connection is terminated. However, PAP is not a strong authentication
process. There is no protection against trial-and-error attacks. The peer is responsible for the
frequency of the authentication communication attempts.
CHAP is a more secure method than PAP. It works by sending a challenge message to the
connection requestor. Using a one-way hash function, the requestor responds with its value. If the
value matches the server’s own calculations, authentication is provided. Otherwise, the connection
is terminated.
Note: RFC1334 defines both CHAP and PAP.