Adtran L768 Manual De Usuario

 

Chapter 1: Understanding HDSL and the Express L768/L1.5

 

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Express L768/L1.5 User Manual

 

The Express L768/L1.5 operates as an IP router when the 

 

 option is configured to 

 

. In PPP mode, the Express L768/L1.5 

uses an IP unnumbered WAN interface; the IP address and mask assigned to 
the unit’s LAN interface apply to all routing and IP operations for the unit.  In 
Frame Relay mode, each PVC can be specified as numbered or unnumbered 
links. If a default gateway is specified on the network of the Ethernet interface, 
the unit attempts to reach the gateway through that interface. If no default 
gateway is specified (i.e., 0.0.0.0) the WAN interface becomes the default gate-
way (recommended for remote applications when there are no other routers 
on the remote LAN).

 

Network routes and services are learned and advertised using Novell’s RIP 
and SAP. 

 

The Express L768/L1.5 can route IP and IPX as well as bridge non-IP/IPX 
packets simultaneously. The PPP profile will by default negotiate PPP net-
work protocols to support the transmission and reception of IP, IPX, and 
Bridge packets. If the PPP peer does not accept a protocol, the Express L768/
L1.5 will fall back to any combination of routing and bridging.

 

NAT is a special mode of operation in which the Express L768/L1.5 obtains a 
dynamically assigned IP address from the peer router (typically an Internet 
Service Provider).  This allows a network of computers to appear as a single IP 
address. 

NAT is enabled if the layer two protocol is PPP and the PPP profile has the IP 
parameter 

 

 set to 

 

, or the layer two protocol is Frame Relay and a 

DLCI mapping has the 

 

 parameter set to 

 

. The network com-

puter’s IP stack may use DHCP to request an IP address, default gateway ad-
dress, and domain name server addresses from the Express L768/L1.5.