Cisco Terminal Server Configuration tips (NHWIC-16A & NM-32A)

"Connection refused by remote host" still appears in telnet host 1015, and an asterisk appears in front of tty. In this case, "clear line tty 68" is required"

Terminal Server Configuration:

The asynchronous port of the terminal server is connected to the console port of the test router using a Cisco flat cable.
Interface loopback0
Ip address 1.1.1.1 255.255.255.255
Exita
Line 1 16
No exec <-Disable the EXEC Process
Transport input all <-Allow all protocols to be used from line 1-16
Exit
Telnet 1.1.1.1 2002 <-reverse telnet to connect to the vro on tty2
Ip host router1 2002 1.1.1.1 <-host table

Terminal_server # show users all <-view the connected user and the connected line

Ctrl + Shift + 6, and then press x <-Return to the terminal server. To exit completely, enter exit on the current interface and press Enter.

Line vty 0
Password cisco
Login
Escape-character W <-change the default exit character to Ctrl + W (default: Ctrl + Shift + 6)

Terminal_server # show sessions <-view the telnet session * as the current session. Press enter to connect. Other numbers are as follows: 2.
Terminal_server # disconnect 2 <-terminate the telnet session (Local to remote)
Terminal_server # clear line 1 <-clear line (from someone else to the local machine)
Terminal_server # show line 1 <-view the line status

TS cable status:
The corresponding indicator is on when the router is connected, and swtich is not on

If the following prompt appears:
% Connection refused by remote host

1. Make sure that the following statements are configured on TS
Line 1 16
No exec
Transport input all

2. Configure the following statements for target device:
Line con 0
Session-timeout 30
Exec-timeout 15 0
Password Wh0ar3Y0u
Line vty 0 4
Session-timeout 30
Exec-timeout 15 0
Password Wh0ar3Y0u
Login
Transport input all
Line vty 5 15
Login

3. If the configuration is correct, "Connection refused by remote host" still appears in the consolde of TS"
Check the physical cables at both ends of TS-target, whether the patch panel is inserted in the connector, and whether the cables at both ends are connected.

4. if you log on to the host --> TS --> target, and "Connection refused by remote host" appears, you need to connect to the TS console and clear the pending (or out of Connection status) sessions

Sh session
Dis 1

Note:
When telnet to TS, you cannot see the suspended or connected session. You must view the session on the console.
Once it is returned to the login host, if you log on to target1 again, you can press 1 to continue, or clear the session first, and then log on again

Ultimate law:

Telnet host 1015 still displays "Connection refused by remote host", and an asterisk appears in front of tty. In this case, "clear line tty 68 (68 is the TTY port number, and the system will display it as 2068 )"

5. cables should not be extended too much

6. Once the connection is stable, do not unplug the cable.

7. HWIC-16A debugging
First check the output of show line command.

The first row is for console. it is always with the lowest number (0) followed by the async lines. the number of async lines varies by platform being used. the reverse telnet ports between 2000-2999 (ascii mode) and 6000-6999 (binary mode) range. the above command output will show the TTY line numbers being used and you have to add that number to 2000 and 6000 for example the first TTY line is 33 its reverse telnet port will be 2033 and 6033.

 

CNCNBEIW335FWAS01 # sh line
Tty Line Typ Tx/Rx A Modem Roty AccO AccI Uses Noise Overruns Int
* 0 0 CTY---12 0 0/0-
1 One AUX 9600/9600---0 0 0/0-
* 0/0/0 2 TTY 9600/9600---4 32 0/0-
0/0/1 3 TTY 9600/9600---2 36 0/0-
If 0/0/0 is connected to rm01, the corresponding reverse telnet port is 2000 + 2 = 2002, and the port cannot be defined as freely as the NM-32A; similarly, 0/0/1 is connected to rm02, the reverse telnet port is 2003.

Ip host rm01 2002 165.46.234.72
Ip host rm02 2003 165.46.234.72
The above rm01 is only a identifier, and the actual identifier is 2002, that is, the device corresponding to the 0/0/0 cable.

8. Do I need a rolover cable if it is used across racks?
No,
Because the cable from Octopus itself is a rolover cable, the common straight-through network cable should be used for cross-rack jumper.

9. How to troubleshoot?

If you cannot connect to the router of your choice with a name configured in the ip host command check:
1. Check whether the port address is configured correctly.
Verify whether the address (interface) used for the reverse Telnet is up/up. The output of the show ip
Interface brief command provides this information. Cisco recommends you to use loopbacks because
They are always up.
2.
Ensure that you have the correct type of cabling. For example, you must not use a crossover cable
Extend the length. Refer to the Cabling section for more information.
3.
Establish a Telnet connection to the IP address port to test direct connectivity. You must telnet from
Both an external device and the terminal server. For example, telnet maid 2003.
4.
Ensure that you have the transport input telnet command under the line for the target device.
Target device is the device that is connected to the terminal server.
5.
Use a PC/dumb terminal to connect directly to the console of the target router. The target router is
Device connected to the terminal server. This step helps you identify the presence of a port issue.
6.
If you are disconnected, check timeouts. You can remove or adjust timeouts.
Note: If you encounter authentication failures, remember that the terminal server performs the first
Authentication (if configured), while the device to which you try to connect performs the second
Authentication (if configured). Verify whether AAA is configured correctly on both the terminal
Server and the connecting device.

This article is from the "Hongqiao walk" blog, please be sure to keep this source http://cnahqmb.blog.51cto.com/55591/718760