Lucent Technologies 6000 - Manual (Page 370)

9-6 MAX 6000/3000 Network Configuration Guide
Configuring IP Routing
Introduction to IP routing on the MAX
System-based routing
With system-based routing, a MAX unit does not assign specific interface addresses to each
WAN connection. It routes packets to the remote network through the WAN interface it created
when the connection was brought up.
Interface-based routing
Interface-based routing uses numbered interfaces. Some routers or applications require
numbered interfaces. Also, some sites use them for troubleshooting leased point-to-point
connections and forcing routing decisions between two links going to the same final
destination. Interface-based routing enables the unit to operate in much the same way as a
multihomed Internet host.
Figure 9-4 illustrates an interface-based routing connection.
Figure 9-4. Interface-based routing example
At Site A, the MAX unit assigns IP addresses 10.5.6.7 and 10.5.6.8 to the WAN interfaces and
uses these interface addresses to route packets to the remote network 10.7.8.10.
Interface-based routing requires that, in addition to the systemwide IP configuration, the unit
and the far end of the link have link-specific IP addresses.
Alternatively, you can omit the remote side’s system-based IP address from the Connection
profile and use interface-based routing exclusively. This is an appropriate mechanism if, for
example, the remote system is on a backbone net that can be periodically reconfigured by its
administrators, and you want to refer to the remote system only by its mutually agreed-upon
interface address.
If a unit uses a numbered interface, note the following differences in operation as compared to
system-based routing:
• IP packets generated in the unit and sent to the remote address have an IP source address
corresponding to the numbered interface, not to the systemwide (Ethernet) address.
• The unit adds all numbered interfaces to its routing table as host routes.
• The unit accepts IP packets addressed to a numbered interface, considering them to be
destined for the unit itself. (The packet can actually arrive over any interface, and the
numbered interface corresponding to the packet’s destination address need not be active.)
10.5.6.7/24
10.2.3.4/24
10.5.6.8/24
10.7.8.9/24
10.2.3.5/24
10.7.8.10/24
Site A Site B
WAN