Lucent Technologies 6000 - Manual (Page 371)

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