Lantronix XPORT PROTM 900-560 - Manual (Page 67)

9: Service Settings
XPort Pro User Guide 67
To find a DNS Name or IP Address:
1. Enter either a DNS name or an IP address.
2. Click Lookup.
 When a DNS name is resolved, the results appear in the DNS cache.
 When an IP address is resolved, the results appear in a text below the Lookup field.
To clear cache entries:
1. Click Remove All to remove all listed cache entries.
2. Click Delete next to a specirfic cache entry to remove only that one.
PPP Settings
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 Pro 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.
The XPort Pro also supports authentication scheme of “None” when no authentication is required
during link negotiation.
Since the XPort Pro does not support Network Address and Port Translation (NAPT), static routing
table entries must be added to the serial-side and network-side devices (both of which are external
devices).
Use the XPort Pro Web Manager or CLI to configure a network link using PPP over a serial line.
Turn off Connect Mode, Accept Mode, and Command mode before enabling PPP. The XPort Pro
device acts as the server side of the PPP link; it can require authentication and assign an IP
address to the peer. Upon PPP configuration, IP packets are routed between Ethernet and PPP
interfaces.
The XPort Pro does not perform network address translation (NAT) between the serial-side
network interface and the Ethernet/WLAN network interface. Therefore, to pass packets through
the XPort Pro, a static route must be configured on both the PPP Peer device and the remote
device it wishes to communicate with. The static route in the PPP Peer device must use the PPP
Local IP Address as its gateway, and the static route in the remote device must use the network
interface IP Address of the XPort Pro as its gateway.