...

1. Open up a terminal for each GENI VM where you want to login (i.e. three terminal windows for this intro tutorial).
2. SSH into each of your resources using your GENI username, the host and domain name of your resource given by the steps above, the port provided, and the path to your downloaded private key. To specify the port number the SSH server has open for you, use the -p SSH flag. To tell your SSH client to use the private key you downloaded from GENI, use the -i flag. For example:
   
3. Repeat step 2 for each GENI resource that you want to login to.
4. Pro tip: Optionally, add your private key to your SSH agent so that it will automatically be tried when you SSH. Use the passphrase you set for the key when you created it on the GENI portal. If you do this, you will not need the -i flag to access any GENI resources in the future.
   

...

Handy Networking Commands

In this course, the projects will require you be familiar with some basic networking tools. This is by no means a comprehensive guide, but it will give you some skills to become dangerous.

ifconfig

ifconfig stands for network "interface configuration". It allows you to not only view information about your system's current network settings, but it also allows you to modify the running configuration.

View Interfaces

Only Interfaces that are Up

Image Added

All Interfaces, Both Up and Down

Image Added

List a Specific Interface

Image Added

Modify an Interface

There are many things we can do to a network interface using ifconfig. One simple example is to bring an interface up that is down.

Image Added

Image Added

route

The route command allows you to see the current routes configured on the system, as well as add and remove existing routes.

View Routes

Add a Route

Remove a Route

tcpdump

tcpdump is a stripped down version of Wireshark that allows us to view packets that are actively entering or exiting the network interfaces of a machine. There are countless tcpdump filters to get the output to show only what we're interested in. Here's a basic example that will show all ARP and ICMP packets on interface eth1. The trailing -e flag is to show Ethernet headers (MAC addresses), and the -vv is to increase the verbosity. 

Image Added

We can also use the -n flag to tell tcpdump to not resolve the host domain names and just give us the raw IP addresses instead. I find this mode of operation easier to follow.

Image Added

ovs-vsctl