Auxiliary Port, Console Port, And Adapter Pinouts

Auxiliary Port, Console Port, And Adapter Pinouts For Cisco 1000, 1600, 2500, 2600, And 3600 Series Routers

The console and auxiliary ports on Cisco IOS routers are asynchronous serial ports. The console port is configured as data communications equipment (DCE), and the auxiliary port is configured as data terminal equipment (DTE). For Cisco 1000, 1600, 2500, 2600, and 3600 series routers, the console and auxiliary ports both use RJ-45 connectors. Adapters are available for connections to PC terminals, modems, or other external communications equipment.

Console Port Pinouts (RJ-45)

Console Port (DTE)
Pin¹	Signal	Input/Output
1	-	-
2	DTR	Output
3	TxD	Output
4	GND	-
5	GND	-
6	RxD	Input
7	DSR	Input
8	-	-

¹ Any pin not referenced is not connected.

Auxiliary Port Pinouts (RJ-45)

Auxiliary Port (DTE)
Pin²	Signal	Input/Output
1	RTS	Output
2	DTR	Output
3	TXD	Output
4	GND	-
5	GND	-
6	RXD	Input
7	DSR	Input
8	CTS	Input

² Any pin not referenced is not connected.

Console Port Connection To A PC

To connect a PC terminal to the console port, use the RJ-45-to-RJ-45 roll-over cable and either the RJ-45-to-DB-25 female DTE adapter or the RJ-45-to-DB-9 female DTE adapter (labeled "TERMINAL"). Below are the pinout descriptions for both DB-9 and DB-25 connections.

Console Port Signaling and Cabling Using a DB-9 Adapter

Console Port (DTE)	RJ-45-to-RJ-45 Roll-Over Cable		RJ-45-to-DB-9 Terminal Adapter	Console Device
Signal	RJ-45 Pin	RJ-45 Pin	DB-9 Pin	Signal
RTS	1³	8	8	CTS
DTR	2	7	6	DSR
TxD	3	6	2	RxD
GND	4	5	5	GND
GND	5	4	5	GND
RxD	6	3	3	TxD
DSR	7	2	4	DTR
CTS	8	1	7	RTS

³Pin 1 is connected internally to Pin 8.

Console Port Signaling and Cabling Using a DB-25 Adapter

Console Port (DTE)⁴	RJ-45-to-RJ-45 Roll-Over Cable		RJ-45-to-DB-25 Terminal Adapter	Console Device
Signal	RJ-45 Pin	RJ-45 Pin	DB-25 Pin	Signal
RTS	1⁵	8	5	CTS
DTR	2	7	6	DSR
TxD	3	6	3	RxD
GND	4	5	7	GND
GND	5	4	7	GND
RxD	6	3	2	TxD
DSR	7	2	20	DTR
CTS	8	1	4	RTS

⁴ You can use the same cabling to connect a console to the auxiliary port.
⁵ Pin 1 is connected internally to Pin 8.

Auxiliary Port Connection To A Modem

To connect a PC terminal to the router, use the RJ-45-to-RJ-45 roll-over cable and either the RJ-45-to-DB-25 female DTE adapter or the RJ-45-to-DB-9 female DTE adapter (labeled "TERMINAL"). Below are the pinout descriptions for both DB-9 and DB-25 connections.

To connect a modem to the auxiliary port, use the RJ-45-to-RJ-45 roll-over cable and the RJ-45-to-DB-25 male DCE adapter (labeled "MODEM"). Below is the pinout description for the modem connection.

Auxiliary Port Signaling and Cabling Using a DB-25 Adapter

Auxiliary Port (DTE)	RJ-45-to-RJ-45 Roll-Over Cable		RJ-45-to-DB-25 Modem Adapter	Modem
Signal	RJ-45 Pin	RJ-45 Pin	DB-25 Pin	Signal
RTS	1⁶	8	4	RTS
DTR	2	7	20	DTR
TxD	3	6	3	TxD
GND	4	5	7	GND
GND	5	4	7	GND
RxD	6	3	2	RxD
DSR	7	2	8	DCD
CTS	8	1	5	CTS

⁶ Pin 1 is connected internally to Pin 8.