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Software Configuration Guide For Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
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Chapter1 Understanding Interface Numbering and Cisco IOS Software Basics
Understanding Interface Numbering
Figure1-6 Cisco 3631 Router Rear View
For the Cisco 3660 router (see Figure1-3), the slots are numbered as follows:
• Slot 0 contains fixed FastEthernet ports and is located at the top of the chassis.
• Slot 1 is at the bottom right (as viewed from the rear of the chassis), near the power supply.
• Slot 2 is at the bottom left.
• Slot 3 is at the right, above slot 1.
• Slot 4 is at the left, above slot 2
• Slot 5 is at the right, above slot 3.
• Slot 6 is at the left, above slot 4.
For the Cisco 3620 and Cisco 3640 routers shown in Figure1-4 and Figure1-5, the slots are numbered
as follows:
• Slot 0 is at the bottom right (as viewed from the rear of the chassis), near the power supply.
• Slot 1 is at the bottom left.
• Slot 2 is at the top right, above slot 0.
• Slot 3 is at the top left, above slot 1.
For the Cisco 3631 router shown in Figure1-6, the slots are numbered as follows:
• Slot 0 for all built-in interfaces like the FastEthernet port at the bottom center near the Console/AUX
ports
• Slot 0 for all WAN interface card (WIC) interfaces
• Slot 1 for network module interfaces at the bottom left.
• Slot 2 for network module interfaces at the top left, above slot 1.