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