Unplug all cables including power. Plugin power, turn on and wait for about 3 minutes. Press reset button on the back for about 5-10 seconds. When it reboots, connect with known working network cable to one of the LAN ports. Use a web browser to connect to 192.168.1.1 Thank you for your feedback! Your feedback is private.
This document explains how to configure Cisco routers and access servers for external modems connected to asynchronous and AUX ports. It explains how to configure the modem to operate properly when connected.
This document addresses connection to a console port, but only with reference to concepts, not actual installation practices. Note: This document is not a reference for the Microcom or MICA modems used internally on the AS5200, AS5300, AS5800, Cisco 2600, or Cisco 3600 routers. This document is also not a reference for synchronous modems, though there can be a number of similarities. This document is a reference for asynchronous modems only. While much of the information here can apply to synchronous modems, do not rely on it when you configure them. There are no specific prerequisites for this document. The information in this document is based on the software and hardware versions below.
Cisco IOS® Software Releases 9.21 and later. A modem that is V.34-capable (or better) Note: This document does not address platforms that have reached End of Life status, such as ASMs, MSMs, CSMs, STS-10s or 500-CSs. The information presented in this document was created from devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If you work in a live network, ensure that you understand the potential impact of any command before you use it. Refer to the for more information on document conventions. The first step to attach a modem to a router is to install the hardware.
The main concerns are which cables to use and why or why not to use the console port for a modem. It is important to connect the modem to the router before you configure the modem in order to verify communication between them. If the cabling is incorrect, the rest of the process fails. As a rule, external modems are built with a female data communications equipment (DCE) DB-25 port for connection to a controlling device such as a PC or a router. This table helps you to select the appropriate cables to make the connection between the router and the modem.
The table also includes information on the required cabling and the types of physical ports on Cisco routers to which you can connect a modem. Router Port Examples of where found Cables Required DB-25 DTE Male DB-25 AUX on the Cisco 4000, 7000, 7200, and 7500. Straight-through DB-25F - DB25M RS-232 cable. DB-25 DCE Female DB-25 console port on the Cisco 4000 and 7000 series. Null-modem DB-25M - DB25M RS232 cable. A rolled RJ-45-RJ-45 with CAB-25AS-MMOD adapters on both ends will work.
DB-60 Sync/async interfaces. Cisco 1005, 1600s, and 2500s; network modules on the Cisco 2600, 3600, and 4000. Cisco-specific cable, the CAB-232MT(=). RJ-45 AUX or CON on the Cisco 2500s, 2600, 3600, AS5200, and AS5300.
Rolled RJ-45-RJ-45 cable with adapter marked 'MODEM' (part number CAB-25AS-MMOD). 68-pin Cisco 2509-2512; network modules on the Cisco 2600 and 3600.
Cisco parts CAB-OCTAL-ASYNC(=) (with connectors marked 'MODEM') and CAB-OCTAL-MODEM(=). 'Smart Serial' WAN interface card (WIC) on 1720 and 2600s. Cisco part CAB-SS-232MT(=). Note: Sync/async interfaces require the physical-layer async configuration command in order to operate in asynchronous mode. Note: The Cisco 1005 requires the IP/ASYNC or the IP/IPX/ASYNC feature set of Cisco IOS Software in order to allow asynchronous mode on its Serial interface.
There are several advantages to connecting a modem to the console port of a router instead of the AUX port. However, the disadvantages are significant. Advantages of connecting a modem on the console port:. You can recover passwords remotely.
You may still need someone on-site with the router to toggle the power. Aside from that, it is identical to being there with the router.
It is a convenient way to attach a second modem to a router without async ports. This is beneficial if you need to access the router for configuration or management and leave the AUX port free for dial-on-demand routing (DDR). Some routers (for example, Cisco 1600s) do not have AUX ports. If you want to connect a modem to the router and leave the serial port(s) free for other connections, the console is the only option.
Disadvantages of connecting a modem on the console port:. The console port does not support RS232 modem control (data set ready/Data Carrier Detect (DSR/DCD), data terminal ready (DTR)). Therefore, when the EXEC session terminates (logout), the modem connection does not drop automatically. The user needs to manually disconnect the session. More seriously, if the modem connection does drop, the EXEC session does not automatically reset.
This can present a security hole, in that a subsequent call into that modem is able to access the console without entering a password. You can make the hole smaller when you set a tight exec-timeout on the line. However, if security is important, use a modem that can provide a password prompt. Unlike other async lines, the console port does not support hardware (Clear to Send/Ready to Send (CTS/RTS) flow control. Cisco recommends that you use no flow control. If data overruns are encountered, however, you can enable software (XON/XOFF) flow control. The console ports on most systems only support speeds of up to 9600 bps.
The console port lacks reverse Telnet capability. If the modem loses its stored initialization string, the only remedy is to physically disconnect the modem from the router and attach it to another device (such as an AUX port or a PC) to reinitialize. If a modem on an AUX port loses its initialization string, you can use reverse Telnet remotely to correct the problem. You cannot use a console port for dial-on-demand routing because it has no corresponding async interface.
Note: The remainder of this document addresses non-console connections. It is essential that you configure the TTY line before you configure or initialize the modem itself. The two main reasons are:. In order to allow reverse Telnet access to the modem. If you change the line speed after the modem is initialized, the modem no longer communicates with the router until it is again told at what speed to talk to the router. In general, this line configuration works best: line 'x' TTY #. AUX port is line 1 on the router, lasttty+1 on the access server, line 65 on the Cisco 2600s and 3620, and line 129 on the Cisco 3640.
Speed 'xxxxx' Set to the highest speed in common between the modem and the port. This value is usually 115200 baud. Stopbits 1 Improve throughput by reducing async framing overhead (default is stopbits 2). Flowcontrol hardware RTS/CTS flow control.
Modem inout Drop connection on loss of DCD (DSR). Cycle DTR for connection close. This command also allows outbound connections to the modem. Transport input all telnet Allow outbound connections to this line. Needed in order to allow reverse Telnet to the modem.
This configuration assumes that the modem always talks to us at 'speed' (which is why you must LOCK SPEED on the modem), that the CD lead of the modem reflects the actual state of the carrier, and that the modem hangs up when the router drops DTR. Avoid substituting autobaud for speed if at all possible since it usually results in lower throughput.
Maximum Speed Supporting platforms and interfaces 38400 Most AUX ports 115200 Cisco 1005, 1600, and 2509 through 2512 AUX on Cisco 2600 and 3600 Modules and WICs that support external asynchronous modems (for example, NM-16A, WIC-2A/S) Note: If you are routing over the AUX port, notice that each character generates a processor interrupt. You can resolve abnormally high CPU utilization when you use a lower AUX port speed.
Cisco recommends you use the modem autoconfigure type command (introduced in Cisco IOS Software Release 11.1), to configure modems attached to async lines. If you use a version of Cisco IOS Software earlier than 11.1, you can use script startup and script reset to configure the modems via a. For most applications, configure a modern modem as this list details:. Reset to factory defaults (use a hardware flow control template if possible). Use hardware (RTS/CTS) flow control. Use normal modem control (hang up on DTR drop; drop DCD on carrier drop). Enable, but do not require, error control (LAP-M V.42 and MNP).
Enable, but do not require, data compression (V.42bis). Enable all modulations supported by the modem. Lock DTE speed at the highest rate supported by both the modem and the async line. Enable autoanswer if needed. When you are in autoanswer mode, ignore the escape sequence ().
Refer to the documentation provided by your vendor or see the page for a list of links to this documentation for details on the command set used by your modem. Cisco IOS Software maintains a set of built-in modemcaps for various internal and external modems. This output shows an example modemcap from Cisco IOS Software Release 11.3(9)T: router# show modemcap default codex3260 usrcourier usrsportster hayesoptima globalvillage viva telebitt3000 microcomhdms microcomserver necv34 necv110 necpiafs ciscov110 mica If you think one of these built-in modemcaps is suitable, you can use the modem autoconfigure type or the modem autoconfigure discovery command: async-1# terminal monitor async-1# debug confmodem Modem Configuration Database debugging is on async-1# configure terminal Enter configuration commands, one per line. End with CNTL/Z. Async-1(config)# line 1 async-1(config-line)# modem autoconfigure discovery async-1(config-line)#.Mar 3 03:02:19.535: TTY1: detection speed (38400) response -OK-.Mar 3 03:02:24.727: TTY1: Modem type is default.Mar 3 03:02:24.731: TTY1: Modem command: -AT&F&C1&D2SO=1H0-.Mar 3 03:02:25.259: TTY1: Modem configuration succeeded.Mar 3 03:02:25.259: TTY1: Detected modem speed 38400.Mar 3 03:02:25.259: TTY1: Done with modem configuration Note: The built-in modemcap mica consists of an &F. You can use it with many modems to reset to factory defaults. Note: Cisco does not warrant the suitability or currentness of the built-in modemcaps for non-Cisco modems.
You can also define your own modemcap and use the modem autoconfigure type command: async-1# terminal monitor async-1# debug confmodem Modem Configuration Database debugging is on async-1# configure terminal Enter configuration commands, one per line. End with CNTL/Z.