Ping & Traceroute Output Characters Legend - Cisco IOS

Ping Command

The ping command in Cisco IOS is used to determine 3 things
 - Connectivity or Active / Inactive state of a remote host
 - Round trip delay in communicating with a host
 - Packet Loss

Following output characters can be obtained after issuing a ping:

Traceroute Command

The traceroute command in Cisco IOS is used to determine the path that packets actually take when traveling to their destination.

Following output characters can be obtained after issuing a traceroute:

Note:- 

Outputs of Cisco ASA for the above basic troubleshooting commands can be slightly different, As an example "?" in a ping command output is used to indicate a simple timeout. Default timeout to get an echo reply is 2 seconds on Cisco routers and Firewalls.

Create a Low Cost Remote Access Server using a Raspberry Pi

Most of the time Network Engineers use a dedicated laptop with internet connection to access and troubleshoot their networks remotely when they do not have physical access. This is what I call a Remote Access Server here (I don't know what others call it) & I am going to create a low cost solution for this using existing software tools you know. I spent about 50$ for the entire setup.

Before you go through this, go through my previous post Get Raspberry Pi into Networking to complete the basic setup needed.

Install TeamViewer & Fine Tuning

Now download Teamviewer Host for Raspberry Pi from here from the Pi's web browser.
Go to Downloads and right click on the package and install it.

After installation is completed, go to the desktop via TightVNC and go to Menu > Internet > TeamViewer Host and accept terms and conditions and on the app, go to settings > Security and disable the random password from drop down menu.

You can enter following command in Terminal to get the Teamviewer ID and other info from CLI.
teamviewer info 

Now enter the following command to set a static password which will really work.
sudo teamviewer passwd <your password>

This password will be used to log into Teamviewer later on.

Now go to Terminal and enter following command to edit the config.txt file to change the console resolution to match your PC. Resolution of my PC is 1920x1080
sudo nano /boot/config.txt

Now uncomment disable_overscan=1 and framebuffer_width, framebuffer_height parameters and change the values like the following capture.

Hit Ctrl+X and Y and Enter to save and exit.
Hit sudo reboot and after reboot access through your PC's Teamviewer giving the ID and password.

Now you can install other necessary software like Wireshark, SecureCRT or PAC Manager to SSH access etc.

Install Wireshark

Enter following command to download and install Wireshark
sudo apt-get install wireshark

Hit Yes for the dialog box which will prompt

Now enter,
sudo usermod -a -G wireshark pi

Hit sudo reboot and after reboot go to desktop from either TeamViewer or TightVNC and got to
Menu > Internet > Wireshark

Install Putty and Console to a Cisco Device

Start with plugging your console cable to one of the USB ports on your Pi.

Enter following command to Install Putty
sudo apt-get install putty

Time to find out the port of the USB-Serial cable is using. Therefore enter,
dmesg | grep tty

Look at the last line which says ttyUSB0  which means my Pi is using ttyUSB0

While selecting Putty's serial connection select /dev/ttyUSB0

Notes:-

Make sure to change default usernames and passwords after everything is done because it is critical to add some security to this box which could manage the network you work with.