Hands-On Networking Thorsten Herfet, Andreas Schmidt, Frank Waßmuth

To clarify the passing criteria for the MMCP project, here are the results of our reference implementation. To pass the project, the residual error ratios must be at least as low as the reference implementation's. Runtimes depend on your hardware, so there might be differences, but must be below the upper bounds mentioned on the task sheet. This also holds for the redundancy you add.

Residual / Errors = Ratio     | Measured   / Ideal Redundancy | Runtime | Pattern
       0 /    210 =     0.00% |   1.00e+00 /         4.86e-06 |    151s | Benevolent_Pattern_1.txt
       0 /    190 =     0.00% |   1.00e+00 /         4.40e-06 |    144s | Benevolent_Pattern_2.txt
       0 /    190 =     0.00% |   1.00e+00 /         4.40e-06 |    142s | Benevolent_Pattern_3.txt
     118 /  21634 =     0.55% |   1.00e+00 /         5.01e-04 |    149s | Adversary_Pattern_1.txt
     135 /  21932 =     0.62% |   1.00e+00 /         5.08e-04 |    166s | Adversary_Pattern_2.txt
     116 /  21851 =     0.53% |   1.00e+00 /         5.06e-04 |    139s | Adversary_Pattern_3.txt
     186 /    442 =    42.08% |   1.00e+00 /         1.02e-05 |    142s | Burst_Pattern_1.txt
     252 /    502 =    50.20% |   1.00e+00 /         1.16e-05 |    150s | Burst_Pattern_2.txt
     366 /    654 =    55.96% |   1.00e+00 /         1.52e-05 |    149s | Burst_Pattern_3.txt

Update: We have changed our reference implementation slightly, to make your life a bit easier and account for data-dependency.

We've been alerted to an error regarding MAC address casing in one of the unit tests provided with the LLDP project.

We have fixed the tests, which you can now also download individually from the materials section. The full agent zip is also updated.

The last line of function test_receive in agent_tests.py is now:

self.assertEqual(printed_message, "LLDPMessage(src_mac=01:23:45:67:89:AD,chassis_id=01:23:45:67:89:AB,port_id=01:23:45:67:89:AB,ttl=120)\n")

Please note the changed casing for src_mac.

There seems to be some confusion about the passing conditions of the programming projects. To reiterate, here are the key points for passing the projects:

• Projects will be graded individually.
  Though we encourage you to talk to your peers, you are not allowed to hand in shared code or code copies.
• You need to complete (and pass) at least one of the projects to qualify for the final exam.
  Completing both projects successfully will give you a 10% bonus on your exam points.
• We will only accept submissions through the Course Management System. Make sure your submissions adhere to the format given in the individual project descriptions. Submissions outside of the Course Management System (e.g. by Email) will not be considered for grading!

We've been alerted to an error in one of the unit tests provided with the LLDP project.

In test/tlvs_test.py the load test contains an error. To fix it simply replace the function test_load.
A correct version of the function looks like this:

def test_load(self):
        ttl_tlv_bytes = '\x06\x02\xF4\x24'
        ttl_tlv = ttl.TLVTTL()
        ttl_tlv.load(ttl_tlv_bytes)
        self.assertEqual(ttl_tlv.ttl(), 62500)

It has been brought to our attention that the test runner we suggested in the LLDP project description is not installed in the lab VM.

To install the nose package you can issue the following command in a terminal of the lab VM:

sudo pip install nose

Afterwards you can run the unit tests as described in the project description.

Hint: You can get more feedback about test execution by running nosetests in verbose mode:

nosetests -v

We have received a few inquiries regarding the use of third-party libraries in the projects. While it is clearly stated in the project description of the Multimedia Coding Pipeline project, we unfortunately forgot to do so for the LLDP-Agent. Sorry for that.

To clarify:
You are not allowed to use any modules/libraries in the projects which are not part of the Python Standard Library or which you have not written yourself.

We have published some additional appliances for GNS3.

If you liked the practical units so far and want to experiment with different software or play around with advanced concepts you should definitely check it out. The gns3-extras package includes an appliance for the BIND DNS server, as well as a Suricata appliance for you to experiment in the field of intrusion detection. You can find the gns3-extras package in the Materials section.

Please note that we are going to have another short unit on Friday, 10th March at 15:00. We want to use this to wrap-up the course, give you details on the projects and provide you with the opportunity to evaluate the course. There will also be a few hints on how to continue, if you want to learn more about networks and telecommunications.

We have released the virtual machine that is used for most of the practical exercises. It gives you an environment to safely experiment with what you learn in the lecture (without interfering or disturbing networks around you).

The lab VM has been built and tested using VirtualBox, which you can download here at no cost.

Please download the lab VM before the start of the course, because we will be using it from day one. It can be found under materials.

Should you have any problems importing the lab VM on your laptop, please stop by or write us an email.

The admission results have been entered. For those of you that did not score enough (>=22) points, please don't be disappointed. This just avoided that you waste time and effort on something you are very unlikely to pass (exams and projects). We will most likely offer the course another time and by then you will have progressed in your studies and have the prerequisites to take this course. While we won't let you take part in this iteration, we are looking forward to see you again in the next.

For those of you who passed: Congratulations! Actually that was most probably the easiest part of the course ;-). Good luck for your exams in the next weeks and we are looking forward to see you on 28th.