Troubleshoot RP Console Line Issues on the NCS6008

Introduction

This document describes how to troubleshoot hardware or communication issues between the console line and the console ports of a Route Processor (RP) on a Cisco 6008 Series Network Convergence System (NCS6008).

Background Information

The NCS6008 RP has three console ports:

• Console Port 0 â€“ This port connects to the console port of Calvados, which is the code name for the virtual machine that provides the administrator plane for the system. During the boot process, console port 0 shows the BIOS screen (relevant if you must change the boot device or similar). The Calvados CLI interface operates in a virtual active/standby manner, which means that if RP0 is the active Calvados CLI/login process and you open a console session to RP1, it is internally redirected to the RP0 Calvados session. This process can create confusion at times, so pay close attention to the prompt in cases where the physical RP with which you interact actually matters. For example, from RP0 of an NCS6008 system: sysadmin-vm:0_RP0#.
  
  
• Console Port 1 – This port connects to the regular Cisco IOS^® XR console and functions just like the console port on any other IOS XR system. During the boot process, RP1 shows the boot messages from the host Operating System (OS), which in this context is the lowest level Linux OS shell. Once the XR OS is booted, the RP that runs the active IOS XR OS responds to a console session with the normal username and password prompt. Once logged in, you can perform any needed actions, subject to the permissions and access levels that are defined in the system configuration. A console session that is initiated to the RP that runs as the standby IOS XR virtual machine gives a familiar This (D)RP Node is not ready or active for login /configuration message.
  
  
• Console Port 2 – This port connects to an internal Cross Cultural Connection (CCC) controller, and (at least for the scope of this document) it does not need to be configured or attached to anything.

Impact and Associated Risks

Normal services are impacted by the process that is described in this document if the console ports are not accessible. There will be no business impact to services.

Before You Begin

Before you attempt the process that is described in the next section, ensure that you do not have cable issues. Use the same cable in order to confirm whether you can console to a different RP.

Also, enter the show process devc-conaux-con command in order to check the system status:

show processes devc-conaux-con

If any issues are discovered, then perform a coredump and restart the process. If the output confirms that there are no issues, then proceed to the next section in order to isolate the issue. 

Here is an example output:

[host:~]$ stty -aF /dev/ttyS0

speed 115200 baud; rows 0; columns 0; line = 0;intr = ^C; quit = ^\; erase = ^?;
 kill = ^U; eof = ^D; eol = <undef>; eol2 = <undef>; swtch = <undef>; start = ^Q;
 stop = ^S;susp = ^Z; rprnt = ^R; werase = ^W; lnext = ^V; flush = ^O; min = 1;
 time = 0;-parenb -parodd cs8 hupcl -cstopb cread clocal -crtscts-ignbrk -brkint
 -ignpar -parmrk -inpck -istrip -inlcr -igncr -icrnl -ixon -ixoff -iuclc -ixany
 -imaxbel -iutf8opost -olcuc -ocrnl onlcr -onocr -onlret -ofill -ofdel nl0 cr0
 tab0 bs0 vt0 ff0-isig -icanon -iexten -echo echoe echok -echonl -noflsh -xcase
 -tostop -echoprt echoctl echoke[host:~]$

Troubleshoot RP Issues

Note: In this example, Console 0 of RP0 is used for troubleshooting purposes. Console troubleshooting must be performed from the host.

Complete these steps in order to isolate the RP issue:

1. Log into the system as an administrator:
   

   RP/0/RP0/CPU0:NCS6008-A#admin
   Tue Mar 17 13:51:05.919 UTC
   
   <username> connected from 127.0.0.1 using console on xr-vm_node0_RP0_CPU0
   sysadmin-vm:0_RP0#

2. From the system administration page, attempt to establish a Secure Shell (SSH) session to the host for Console 0.

   Note: The IP address  for Console 0 in this example is 10.0.2.2.

   sysadmin-vm:0_RP0# run chvrf 0 ssh 10.0.2.2
   Thu Mar  12 05:03:37.262 UTC
   [host:~]$
   [host:~]$ >> Console 0 host.

3. In order to isolate the direction of the loss, run an echo test from the host to the console line, and from the console line to the host. In this example, a Hello I am console 0 message is sent from the host to the console line:
   

   host:~]$ echo Hello I am console 0 >/dev/ttyS0 >> Sending from S0 i.e. Console0
   
   [host:~]$

   On the console line, you can see the message that was sent from the host of Console 0:
   

   Connecting to Device Port 30.Connected to port 30. Escape sequence is ESC A TEST
    Hello I am console 0

4. In order to confirm that communication occurs between the console line and the Console 0 host, enter some text on the console line. You will not be able to see what is being typed, but it will print at the host end:
   

   [host:~]$ cat < /dev/ttyS0 >>>
   
   Connecting to Device Port 30.Connected to port 30. Escape sequence is ESC A
    <Typed Hello console 0 redirect.>

   As shown, you can see the same characters appear on the Console 0 host:
   

   [host:~]$
   Hello console 0 redirect. >>> Message coming from console line. 

5. After you have confirmed that communication occurs both ways, you can attempt to clear the noise on the console line from the host of Console 0:
   

   [sysadmin-vm:0_RP0:~]$ stty -F /dev/hvc0 -ignpar -ignbrk[sysadmin-vm:0_RP0:~]$
   
   [Console Server ]> c d d 30
   Connecting to Device Port 30.Connected to port 30. Escape sequence is ESC A
   
   sysadmin-vm:0_RP0# run
   Thu Mar  12 05:18:14.486 UTC
   [sysadmin-vm:0_RP0:~]$ stty -F /dev/hvc0 -ignpar -ignbrk
   [sysadmin-vm:0_RP0:~]$

Note: If this process resolves the issue, then you might have encountered Cisco bug ID CSCuq84495.