Ip Routing - ADTRAN Express L128T S User Manual

Chapter 1. Understanding ISDN and the Express L128T S/T
crossing the link. The bridged connection is terminated when the
Hang-up option is selected from the Dial menu, but will redial if the
demand filter condition is met.

IP Routing

The Express L128T S/T operates as a dial-up IP router when the Con-
figuration/IP/IP Router/Mode option is configured to On. The Ex-
press L128T S/T 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. If a default gateway is specified
on the network of the Ethernet interface, the unit attempts to reach the
gateway through that interface. If the gateway is specified on an un-
known network, the unknown network is assigned to the router table
and remains unused until that gateway becomes the peer on a WAN
connection. If no default gateway is specified, the first connected peer
on the WAN interface becomes the default gateway (recommended
for remote applications when there are no other routers on the remote
LAN).
For each profile in the Connection List that includes an IP address and
has the Configuration/Connection List/IP/Route/Static Route option
set to Yes, the Network Address of the specified IP address is added
to the router table with the Host Address as the gateway. If the Con-
figuration/Connection List/IP/Route/Private option is set to No, the
route is advertised at the specified metric through the unit's interfaces
as if a connection is active to that network. These routes are referred
to as spoofed routes.
Attempts by any computer connected to the LAN interface to access a
host on a spoofed network causes a connection to be attempted using
the information from that Connection List profile. Once connected,
routes advertised by the peer router are learned and advertised to the
local LAN. If Bandwidth-On-Demand is enabled and an Idle Time-
out value is specified, expiration of the Idle Timer causes the link to be
disconnected; the routes learned from the peer router are retained if
the Configuration/Connection List/IP/RIP/Retain option is set to Yes
and advertised as if the connection is still active. These routes are re-
ferred to as retained routes. Attempts by any connected computer to ac-
cess a host on any of the retained routes causes the link to be redialed.
1-8 Express L128T S/T User Manual 61202070L3-20