User DOs and DON'Ts

Each DETER node has several network interfaces. One of those is always connected to the "control net" and used to send reboot signals, OS load and similar control info to the node. The other interfaces are for experimental use. These are connected in the topology you specified when you created the experiment. You should only use control network when absolutely necessary, i.e. there is no other way to achieve the effect you desire. Using it more often will create load for everyone on the testbed and will result in wrong results in many exercises. Your instructor should've included in your exercise assignment all the guidelines to minimize traffic on the control network. Here are a few things to keep in mind as you proceed:

Unless otherwise required in your exercise use "short" DNS names when you send traffic between your nodes. For example if you have node1 and node2 in your topology to ping node2 from node1 you would ssh into node1 from users.deterlab.net by doing: ssh node1.YourExperiment.YourProject.isi.deterlab.net and then issue a command on node1 ping node2 The first command (SSH) went over the control network, as this was the only way to go from users machine into your experiment. The second command (ping) went over the experimental network, which is what you wanted. Traffic from experimental nodes to/from your home directory also travels over the control network (read more about this in the next section). To minimize this load please refrain from performing large (> 500 MB) or frequent (< 10 s) reads/writes that involve your experimental nodes and your home directory, unless absolutely necessary. If you need to log something, use a local directory on an experimental node, such as /tmp, and transfer the logs to your home directory before you swap out to save them.