Cisco devices, routers, and switches typically interconnect many devices. For this reason, these devices have several types of ports and interfaces that are used to connect to the device. For example, a Cisco 1941 router backplane includes the connections and ports described in the figure. Click each highlighted area to view more information.
Like many networking devices, Cisco devices use light emitting diode (LED) indicators to provide status information. An interface LED indicates the activity of the corresponding interface. If an LED is off when the interface is active, and the interface is correctly connected, this may be an indication of a problem with that interface. If an interface is extremely busy, its LED is always on.
Enhanced High-speed WAN Interface Card (eHWIC)
Labeled as eHWIC 0 and eHWIC 1 to provide modularity and flexibility by enabling the router to support different types of interface modules, including serial, digital subscriber line (DSL), switch port, and wireless.
Compact Flash Slots
Labeled as CF0 and CF1 to provide increased storage flash space upgradable to 4 GB compact flash card per slot. By default, CF0 is populated with a 256 MB compact flash card and is the default boot location.
For the initial configuration and command-line interface (CLI) management access. Two ports are available; the commonly used regular RJ-45 port and a new USB Type-B (mini-B USB) connector. However, the console can only be accessed by one port at a time.
Ports labeled as USB 0 and USB 1 to provide additional storage space similar to flash.
Interfaces labeled as GE0/0 and GE0/1. Typically used to provide LAN access by connecting to switches and users, or to interconnect to another router.
RJ-45 port for remote management access similar to the Console port. Now considered a legacy port as it was used to provide support for dial-up modems.