ADTRAN 1200350L1, User Manual

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Chapter 1: Introduction
61200350L1-1 Router Option Module User Manual 1-3
terface. The IP address and mask assigned to the unit’s LAN inter-
face 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 gateway (recom-
mended for remote applications when there are no other routers on
the remote LAN).
IPX Routing
Network routes and services are learned and advertised using No-
vell’s RIP and SAP.
Concurrent Routing and Bridging
The Router Option Module can route IP and IPX as well as bridge
nonIP/IPX packets simultaneously. The PPP profile will, by default,
negotiate PPP network protocols to support the transmission and
reception of IP, IPX, and Bridge packets. If the PPP peer does not ac-
cept a protocol, the Router Option Module will fall back to any com-
bination of routing and bridging.
Network Address Translation Mode (NAT)
NAT is a special mode of operation in which the Router Option
Module obtains a dynamically assigned IP address from the peer
router (typically an Internet Service Provider). This allows a net-
work of computers to appear as a single IP address.
NAT is enabled if the layer 2 protocol is PPP and the PPP profile has
the IP parameter NAT set to Yes, or the layer 2 protocol is Frame Re-
lay and a DLCI mapping has the IP MAP/NAT parameter set to
Yes
.
The network computer’s IP stack may use DHCP to request an IP
address, default gateway address, and domain name server ad-
dresses from the Router Option Module.