1-2
Software Configuration Guide For Cisco 2600 Series, Cisco 3600 Series, and Cisco 3700 Series Routers
OL-1957-04
Chapter1 Understanding Interface Numbering and Cisco IOS Software Basics
Understanding Interface Numbering
Note The number and type of interfaces vary depending on the router.
WAN and LAN Interface Numbering
The Cisco 2600 series router chassis contains the following wide-area network (WAN) and local-area
network (LAN) interface types:
• Built-in LAN interfaces: Ethernet, FastEthernet, Token Ring
• Two or three slots in which you can install WAN interface cards (WICs)
• One slot in which you can install a network module
The numbering format is Interface-type Slot-number/Interface-number. Two examples are:
Ethernet 0/0
Serial 1/2
The slot number is 0 for all built-in interfaces and 0 for all WIC interfaces; the slot number is 1 for
network module interfaces.
Table1-1 Router Models
Model
Ethernet
(10BASE-T)
Token-Ring
(RJ-45)
Fast Ethernet
(10/100)
Network
Module Slot
WAN
Interface
Card Slots
Advanced
Integration
Module Slots
Cisco 2610 1 1 2 1
Cisco
2610XM
1 1 2 1
Cisco 2611 2 1 2 1
Cisco
2611XM
2 1 2 1
Cisco 2612 1 1 1 2 1
Cisco 2613 1 1 2 1
Cisco 2620 1 1 2 1
Cisco
2620XM
1 1 2 1
Cisco 2621 2 1 2 1
Cisco
2621XM
2 1 2 1
Cisco 2650 1 1 2 1
Cisco
2650XM
1 1 2 1
Cisco 2651 2 1 2 1
Cisco
2651XM
2 1 2 1
Cisco 2691 2 1 3 2