Understanding Interface Numbering
Figure 1-11
A WIC in each of the three WAN interface card slots
•
A single-width network module in each of the four network module slots
•
Two AC power supplies
•
Figure 1-11 Cisco 3745 Rear Panel
10
1 Console port
2 Auxiliary port
3 FastEthernet 0/1
4 FastEthernet 0/0
The slot number for all WIC interfaces is always 0. (The W0, W1, and W2 slot designations are for
Note
physical slot identification only.) Interfaces in the WICs are numbered from right to left, starting with
0/0 for each interface type, regardless of which physical slot the WICs are installed in. Some
examples are:
–
–
–
Software Configuration Guide For Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
1-12
shows the rear panel of the Cisco 3745 with:
1
8
9
7
6
If physical slot W0 is empty and physical slot W1 contains a 1-port serial WIC, the interface in
the WIC is numbered Serial 0/0.
If slot W0 contains a 2-port serial WIC and slot W1 contains a 1-port serial WIC, the interfaces
in physical slot W0 are numbered Serial 0/0 and Serial 0/1, and the interface in physical slot W1
is numbered Serial 0/2.
If slot W0 contains a 2-port serial WIC and slot W1 contains a 1-port BRI WIC, the interfaces
in physical slot W0 are numbered Serial 0/0 and Serial 0/1, and the interface in physical slot W1
is numbered BRI 0/0.
Chapter 1
Understanding Interface Numbering and Cisco IOS Software Basics
5
4
2
3
5 Compact Flash slot
6 Power supplies
7 Network module slots
8 WAN or voice interface card slots
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