Lucent Technologies 6000 User Manual

Page of 586
Configuring IP Routing
Configuring LAN interfaces
MAX 6000/3000 Network Configuration Guide
 9-7
Configuring LAN interfaces 
To configure the LAN interface for IP routing, you need to establish an IP address, enable 
routing table updates, and configure Address Resolution Protocol (ARP) responses. The 
parameters for configuring the LAN interface are located in the Ethernet menu’s profiles.
Configuring primary and secondary IP addresses for the LAN
The Ethernet > Mod Config > Ether Options > IP Adrs parameter specifies a primary IP 
address for the LAN (Ethernet) interface. When you specify an IP address for a MAX unit, you 
must assign a subnet mask or the MAX unit assigns a subnet mask based upon the class of the 
IP address you assign.
You can also set the Ethernet > Static Rtes > Gateway parameter to assign the IP address of the 
next-hop router that a packet must go through to reach a route’s destination.
You can specify two unique IP addresses for the single physical Ethernet port on the MAX 
unit. Although devices connected to the same physical wire usually belong to the same IP 
network, this feature, referred to as dual IP, gives the unit a logical interface on two networks 
or subnets on the same backbone.
Dual IP is also used to distribute the routing of traffic to a large subnet, by assigning IP 
addresses on that subnet to two or more routers on the backbone. When a router has a direct 
connection to the subnet as well as to the backbone network, it routes packets to the subnet and 
includes the route in its routing table updates.
In addition, you can use dual IP to enable a smooth transition when changing IP addresses. The 
second IP address can act as a placeholder while you are making the transition in other network 
equipment.
To configure dual IP, you use the 2nd Adrs parameter along with the IP Adrs parameter to 
specify IP addresses for the two different networks or subnets. For example, Figure 9-5 shows 
two IP addresses (12.1.1.1 and 13.9.7.5) assigned to the MAX unit’s Ethernet interface. The 
unit routes between all displayed networks. Packets routed through 12.1.1.1 can be delivered to 
hosts 12.1.1.2 and 12.1.13. Packets routed through 13.9.7.5 can be delivered to hosts 13.1.2.3 
and 13.6.7.8. The host 12.1.1.2 and the host assigned 13.1.2.3 share a physical cable segment, 
but do not communicate directly. The MAX unit must route traffic between the two networks.
Figure 9-5.  Sample dual IP network
Address=12.1.1.2
Address=12.1.1.3
Address=13.6.7.8
Address=13.1.2.3
IP Adrs =12.1.1.1
2nd Adrs =13.9.7.5