Cisco 2600 Series Operation Manual page 17

Cisco 2600 Series Interface Numbering
Each individual network interface on a Cisco 2600 series router is identified by a slot
number and a unit number.
Slot and Unit Numbering
The Cisco 2600 series router chassis contains one slot in which you can install a network
module. This is always slot 1.
Unit numbers identify the interfaces on the modules and WAN interface cards installed in
the router. Unit numbers begin at 0 for each interface type, and continue from right to left
and (if necessary) from bottom to top. Modules and WAN interface cards are identified by
interface type, slot number, followed by a forward slash (/), and then the unit number; for
example, Ethernet 0/0.
Figure 1-4 shows a router with a 2E 2-slot module in slot 1. One serial and one ISDN BRI
WAN interface card are installed in the module.
Figure 1-4 Cisco 2600 Series Unit Numbers
BRI 1/0
Serial 1/0
Ethernet Ethernet
1/0
1/1
Note
if the interface card is installed in the slot labeled W1.
Serial 0/1 Serial 0/0
W1
W0
LINK TOKEN RING 0/0
ACT
LINK ETHERN ET 0/0 ACT
CONSO LE
Ethernet
0/0
Token
Console
Ring 0/0 port
WAN interface card slots (built into the chassis) are always numbered as slot 0, even
Cisco 2600 Series Interface Numbering
Cisco 2612
100-240 V– 1A
50/60 Hz 47 W
W0
AUX
Auxiliary
port
Overview of Cisco Network Modules 1-9