Preparing To Make Connections; Slot Numbering; Unit Numbering - Cisco EF4116 Hardware Installation And Maintenance Manual

Preparing to Make Connections

When viewed from the rear, the power cable and power switch appear on the right side of the router
chassis. The system console port, auxiliary (AUX) port, and network processor module ports appear
to the left of the power cable and switch. (See Figure 2-2.)
Figure 2-2
Token Ring port
Token Ring module

Slot Numbering

The chassis contains slots for three network processor modules. These slots correspond to the three
slot numbers printed on the chassis front panel. (See Figure 1-1.) Slot numbers represent the order
in which the system scans the network processor modules. Network processor module location is not
slot-dependent. Any module can be moved to any other available slot location. For optimum heat
dissipation, use the center slot position, slot 2, for the FDDI module if one is present.
For information on how to remove and replace network processor modules, see the sections
"Removing Network Processor Modules" and "Replacing Network Processor Modules" in the
chapter "Maintaining and Upgrading the Router."

Unit Numbering

Unit numbering allows the system to distinguish between two interfaces of the same type. As viewed
from the rear of the chassis, the unit numbering of the network processor modules increments from
zero counting from the right to left. The system assigns unit number addresses to these network
modules by starting with zero for each module interface type and numbering from right to left and
from bottom to top. The lowest unit number of that interface type is the module closest to the power
supply. (See Figure 2-2.) For example, the unit number addresses for the modules in Figure 2-2 are
as listed in Table 2-1.
Table 2-1
Slot No.
1
2
3
Router—Rear View Showing Slot Numbering and Interface Ports
10BaseT
port
Slot 3
Ethernet
port
Ethernet module
Auxiliary port
Unit Numbering for Dual Serial, Ethernet, and Token Ring Modules
Interface Type
Serial Port (Top)
Serial Port (Bottom)
Ethernet
Token Ring
Chassis Serial interface ports
release screw
Dual serial
Slot 2
module
Console port
Unit Address No.
1
0
0
0
Preparing to Make Connections
Slot 1
Power On/off switch
Preparing for Installation 2-7