05-14-2008 08:08 AM - edited 03-05-2019 10:58 PM
05-14-2008 01:15 PM
mahesh
I am not sure that I understand quite what you are asking here. So let me explain it this way and if that does not answer your question then perhaps you can clarify so that I can understand better and give a better answer.
In essence we are talking here about syslog. There are many system messages that can be written to syslog - including debug messages. Syslog messages can be sent to several different destinations including: to the console, to the logging monitor, and to the logging buffer. It is possible to configure a severity level of messages that will be written to each of these destinations. Assuming that the same severity level is configured then the content of syslog messages (including debug) sent to the console will be the same as the content of syslog messages sent to logging monitor, and the same as the content of syslog messages sent to logging buffer.
The main difference in these logging destinations is how you view the messages. If you are connected to the console you will see the logging messages displayed on the console in real time. If you have a remote session (telnet or SSH) and if you enter the command terminal monitor, then you will see the messages in your session in real time. Or the console or a remote session can use the command show log and will see the messages that have been previously written to the log (messages not viewed in real time).
HTH
Rick
05-14-2008 09:56 AM
mahesh
I am not clear what you are really asking. So let me explain a few things and if it does not answer your question then please clarify for us what you are asking.
debug is a diagnostic utility that runs on Cisco. It can analyze and display many aspects of the operation of the Cisco. The output from debug is sent to the console by default. You can control whether the console displays the debug output by controlling the severity level of messages sent to the console. For example if you were to configure this:
logging console info
then it will set the severity level to not show debug output. (note that the default is logging console debug which does include the debug output).
An option is to send debug output to the monitor, which makes the debug available to a telnet session. If you telnet to Cisco and then enter the command:
terminal monitor
then it will send copies of the debug output to your telnet session.
HTH
Rick
05-14-2008 11:14 AM
Hi rick,
Thanks for reply .
So console debugging is when some one gets cosole connection to router and we can view
the debugs which command we use to view the console debugging?
I wanted to know basically what is console and monitor debug mean?Also buffer logging
is when router logs message to internal memory?which memory it stores buffer logging
and if we want to see output of buffer debugg
will it be shown by sh log command?
05-14-2008 11:38 AM
mahesh
You can initiate debug from a session on the console or from a remote session on the vty ports (telnet or SSH). When debug is running it sends its output to the destinations that I discussed.
On the console the output is just displayed on the terminal. No command is required for this. Note that the console is a terminal that is direct wired to the console port of the Cisco.
the monitor displays its output (including debug output) in real time. It is intended for remote sessions on the vty ports (telnet or SSH) and monitor is not available on the console. The command to initiate display of monitor outout is terminal monitor.
logging buffer stores its output in memory that is dynamically allocated for this purpose. Its display is not real time (a difference from logging monitor) and is available for display after the debug has run. The command to see the messages in the logging buffer is show log.
HTH
Rick
05-14-2008 11:57 AM
Hi Rick,
thanks for reply again.
so if someone enable the console debugging on
router.then case 1----no one has console connection to router console port of router
in this case we will see console debugging by --sh log on router?
Case2--console debugg is enabled and someone has console connection to router port in this
case output of console debugg will be on router?if on router then if i telent the router sametime will it show both console and monitor debugg?
05-14-2008 12:08 PM
mahesh
in case 1 if no one has a connection on the console port then no one will see the console debug output. sh log will not show console output but will show logging buffer output.
Note that the content of debug output sent to the console is the same as the content of debug output sent to logging buffer.
in case 2 if someone has an active connection on the console then they will see the console debug output. If you then telnet to the router it will be a different session because telnet is a remote access and console is a local access. If you telnet then you can use terminal monitor to see the debug output in your telnet session. And yes both console output and monitor output can be shown at the same time.
HTH
Rick
05-14-2008 01:03 PM
Hi rick
thanks for reply once again
so this line
Note that the content of debug output sent to the console is the same as the content of debug output sent to logging buffer.
this means that if some one has console debug on and console connection to router
the conents that user sees on his laptop is same as sh log buffer command??????????
05-14-2008 01:15 PM
mahesh
I am not sure that I understand quite what you are asking here. So let me explain it this way and if that does not answer your question then perhaps you can clarify so that I can understand better and give a better answer.
In essence we are talking here about syslog. There are many system messages that can be written to syslog - including debug messages. Syslog messages can be sent to several different destinations including: to the console, to the logging monitor, and to the logging buffer. It is possible to configure a severity level of messages that will be written to each of these destinations. Assuming that the same severity level is configured then the content of syslog messages (including debug) sent to the console will be the same as the content of syslog messages sent to logging monitor, and the same as the content of syslog messages sent to logging buffer.
The main difference in these logging destinations is how you view the messages. If you are connected to the console you will see the logging messages displayed on the console in real time. If you have a remote session (telnet or SSH) and if you enter the command terminal monitor, then you will see the messages in your session in real time. Or the console or a remote session can use the command show log and will see the messages that have been previously written to the log (messages not viewed in real time).
HTH
Rick
05-14-2008 02:57 PM
Hi rick
thanks for all your replies
many thanks
05-14-2008 05:55 PM
mahesh
I am glad that my answers have been helpful for you. Thank you for using the rating system to indicate that your question was resolved (and thanks for the ratings). It makes the forum more useful when people can read a question and can know that there were responses that helped to resolve the question.
The forum is an excellent place to learn about Cisco networking. I encourage you to continue your participation in the forum.
HTH
Rick
05-14-2008 11:40 AM
Hi Rick also one more thing
when i do sh log on router it shows
Monitor logging: level debugging, 84 messages logged, xml disabled,
filtering disabled
so this shows terminal monitor is enabled?
when i ran the command terminal monitor i get
these reply
14 14:37:50 extende: %SEC-6-IPACCESSLOGP: list DCOMinA permitted tcp 10.12.29.79(135) -> 10.10.144.54(3372), 1 packet
May 14 14:37:56 extende: %SEC-6-IPACCESSLOGP: list DCOMoutA permitted udp 10.6.49.58(0) -> 10.12.29.95(0), 1 packet
May 14 14:38:15 extende: %SEC-6-IPACCESSLOGP: list DCOMoutA permitted udp 10.37.2.13(0) -> 10.18.30.80(0), 1 packet
May 14 14:38:17 extende: %SEC-6-IPACCESSLOGP: list DCOMinA permitted udp 10.18.34.182(0) -> 10.37.2.13(0), 1 packet
May 14 14:38:19 extende: %SEC-6-IPACCESSLOGRL: access-list logging rate-limited or missed 7 packets
May 14 14:38:20 extende: %SEC-6-IPACCESSLOGP: list DCOMoutA denied tcp 10.50.17.35(1352) -> 10.12.214.159(1171), 1 packet
May 14 14:38:25 extende: %SEC-6-IPACCESSLOGP: list DCOMoutA permitted udp 10.37.2.13(0) -> 10.18.42.201(0), 1 packet
also when i do sh terminal command
i get this
sh terminal
Line 2, Location: "", Type: "XTERM"
Length: 70 lines, Width: 198 columns
Baud rate (TX/RX) is 9600/9600
Status: PSI Enabled, Ready, Active, No Exit Banner, Automore On
Capabilities: none
Modem state: Ready
Special Chars: Escape Hold Stop Start Disconnect Activation
^^x none - - none
Timeouts: Idle EXEC Idle Session Modem Answer Session Dispatch
00:12:00 00:30:00 none not set
Idle Session Disconnect Warning
never
Login-sequence User Response
00:00:30
Autoselect Initial Wait
not set
Modem type is unknown.
Session limit is not set.
Time since activation: 00:07:12
Editing is enabled.
History is enabled, history size is 20.
DNS resolution in show commands is enabled
Full user help is disabled
Allowed input transports are pad telnet rlogin mop v120 ssh.
Allowed output transports are pad telnet rlogin mop v120 ssh.
Preferred transport is telnet.
No output characters are padded
No special data dispatching characters
so my question is is termianl monitor configured on this router???????????
Many thanks
05-14-2008 12:13 PM
mahesh
terminal monitor is certainly configured on that router. if terminal monitor were not configured you would not have gotten this output:
14 14:37:50 extende: %SEC-6-IPACCESSLOGP: list DCOMinA permitted tcp 10.12.29.79(135) -> 10.10.144.54(3372), 1 packet
May 14 14:37:56 extende: %SEC-6-IPACCESSLOGP: list DCOMoutA permitted udp 10.6.49.58(0) -> 10.12.29.95(0), 1 packet
May 14 14:38:15 extende: %SEC-6-IPACCESSLOGP: list DCOMoutA permitted udp 10.37.2.13(0) -> 10.18.30.80(0), 1 packet
May 14 14:38:17 extende: %SEC-6-IPACCESSLOGP: list DCOMinA permitted udp 10.18.34.182(0) -> 10.37.2.13(0), 1 packet
May 14 14:38:19 extende: %SEC-6-IPACCESSLOGRL: access-list logging rate-limited or missed 7 packets
May 14 14:38:20 extende: %SEC-6-IPACCESSLOGP: list DCOMoutA denied tcp 10.50.17.35(1352) -> 10.12.214.159(1171), 1 packet
May 14 14:38:25 extende: %SEC-6-IPACCESSLOGP: list DCOMoutA permitted udp 10.37.2.13(0) -> 10.18.42.201(0), 1 packet
So getting that output is a verification that terminal monitor (and logging monitor) are configured and active.
I am not sure why you are asking about the show terminal command. It has nothing to do with showing debug output on the terminal. show terminal just shows how the terminal port is set up and is operating.
HTH
Rick
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