where are cisco ios debug output messages sent by default?

Cisco IOS is a widely used operating system for various networking devices such as routers and switches from Cisco Systems. As with most network management systems, monitoring and troubleshooting of issues can be critical tasks that require detailed information about the device's operation.

One important feature in this context are debug messages which provide valuable insights into what exactly happens within the IOS when certain events or conditions occur on a running system - but by default these precious logs aren't even being stored anywhere!

To change this behavior and have your debugging output sent somewhere useful instead of just vanishing into thin air (or more accurately: onto whatever console is currently connected to your router), you'll need follow some simple steps:

1. Log in via Telnet/SSH or through the device's physical console port.

2. Once logged-in, enter privileged mode by typing 'enable' followed by your password if prompted.

Now that we're all set up and ready to roll out our first commandlet let's go ahead and configure logging!

To enable global system log (Syslog) output for debugging purposes on Cisco IOS devices:

a' Issue the following commands from within privilege EXEC mode:

```

# show running | include syslog

```

This will display current configuration settings related to Syslog.

b' If necessary, add or modify existing lines under `logging` subconfiguration block like so:

```cisco_ios(config)# logging buffered 25600 debug

```

Here's a breakdown of what each part does:

- buffered: This keyword specifies whether the output should be stored in RAM (RAM buffer) before being sent over serial link; otherwise, it'll go straight into console.

- '25600' is an example size limit for our log file - adjust according to your needs.

c' Finally, save changes by typing `wr` followed by Enter key:

```

# copy running startup

```

After completing these steps, whenever any debug message gets generated due some event or condition being met on the router/switches managed under this particular IOS instance; those important logs will now be automatically saved within their respective log files located at /var/log directory (default location may vary depending upon specific IOS version used).

Where are cisco ios debug output messages sent by default?