User's Manual

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Cisco 1800 Series Routers (Modular) Hardware Installation Guide
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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)
Ta b l e 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