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Cisco 1800 Series Routers (Modular) Hardware Installation Guide
OL-5876-03
Chapter 2 Overview of Cisco 1800 Series Routers (Modular)
Interface Numbering
Interface Numbering
Each individual interface (port) on a Cisco 1841 router is identified by a number. A Cisco 1841 router
contains the following wide-area network (WAN) and local-area network (LAN) interface types:
•
Two onboard Fast Ethernet LAN interfaces
•
Two slots in which you can install WICs, VWICs (data only), and HWICs.
The numbering format for the slots is
interface-type 0/slot-number
/
interface-number
.
Table 2-6
summarizes the interface numbering.
Note
On the Cisco 1841 router, the numbering format for configuring an async interface is
0/slot
/
port
. To
configure the line associated with an async interface, simply use the interface number to specify the
async line. For example, line 0/0/0 specifies the line associated with interface serial 0/0/0 on a WIC-2A/S
in slot 0. Similarly, line 0/1/1 specifies the line associated with interface async 0/1/1 on a WIC-2AM in
slot 1.
1
Input power connection
8
CompactFlash memory card slot
2
On/Off switch
9
CompactFlash (CF) LED
3
Slot 0 (WIC, VWIC—data only, or HWIC)
10
AIM LED
4
Console port
11
USB port
5
Fast Ethernet ports and LEDs
12
Aux port
6
Kensington
TM
security slot
13
Chassis ground connection
7
Slot 1 (WIC, VWIC—data only, or HWIC)
Table 2-6
Interface Numbering
Slot Number
Slot Type
Slot Numbering Range
Example
1
1.
The interfaces listed are examples only; other possible interface types are not listed.
Onboard Ports
Fast Ethernet
0/0 and 0/1
interface fastethernet 0/0
Slot 0
HWIC/WIC/VWIC
2
2.
VWICs are data-only in a Cisco 1841 router.
0/0/0 to 0/0/3
interface serial 0/0/0
line async 0/0/0
Slot 1
HWIC/WIC/VWIC
2
0/1/0 to 0/1/3
interface serial 0/1/0
line async 0/1/0
