There is a problem with episode 9 of the podcast. A large portion of one of the voice tracks is missing. That’s why there are long breaks in the audio. I’ll re-record this an put up a new version of the lecture.
Just a friendly reminder, please don’t forget to take the exam on blackboard.
Tonight was my introduction to text based protocols lab. I have the students use netcat to interact directly with web servers and e-mail MTAs to experience the give and take of layer seven. The dance of GETs and 200 OKs or the chatty email flow using HELO, MAIL FROM, RCPT TO, DATA, and QUIT. When I first started teaching this lab I could use the college’s web and mail server. I also used to be able to let students traceroute and ping in week one during the how big and fast is the Internet lab.
As the years tick by I’ve noticed that these types of explorations of how the Internet works don’t seem to work as well as they once did. I’ve resorted to traceroute.org for my how big is the Internet lab and I need to maintain an old Sun Sparc machine running an old version of sendmail for the email lab.
It’s a mixed blessing in the end. I have to start talking about network security on day one, that’s a good thing. But, I also have to explain security related topics before the students grasp the basics and I’ve got to maintain old gear with old software just to let students get that experiential learning. Perhaps I’ll move some of these labs to more passive methods, i.e. watch an email move from client to server with wireshark.
Somehow it doesn’t feel the same as creating the raw email on the fly. I guess that’s the price we pay living on the dangerous Internet of 2008.
[podcast]http://www.skoda.net/podcast/cis2151-ep9.mp3[/podcast]
This lecture focuses on firewalls and some of the ports you should know for the quizzes and tests, like ssh is tcp/22, telnet tcp/23, smtp tcp/25, web tcp/80, https tcp/443
The medi-vac has finished up in our parking lot and I’m on the way to lab. I’ll be in Green 111 in about 40 minutes.
I’m going to be late to lab, probably very late, in fact, for those of you in the Tuesday lab, you’re probably not going to see me tonight. Someone was injured here in Northfield and the DART is landing in our parking lot to take the injured party to Dartmouth. That means that I’m not going anywhere in my car until the helicopter lands, transfers the patient, and then takes off.
I really don’t know when I’ll be free to drive to Randolph, but let’s just call tonight a wash for lab. I’ll still post the lab hand out in the forums and you can try it on your own, or come down to lab on Wednesday or Thursday night.
You can wait. I am going to swing by lab tonight in order to make sure that the lab test machine we need will work. I’ve got to boot it up and make sure the security restrictions are relaxed enough for the lab to work. If people stay in the lab tonight and wait for me, we can do the lab. What I don’t want is for people to sit and wait without knowing, a) when I’ll be there, 2) if the lab is really cancelled, or iii) where I am.
I’ll twitter and update this blog when I get the all clear from the Northfield PD that I can get out.
I had a lengthy lay over in Chicago and wandered the terminal for a few hours. I happened upon the Mont Blanc store and I inquired about the Jules Verne collection. That’s one of my fantastic items to purchase when I become independently wealthy. They had a Faulkner in the case, so I figured I’d ask to see what other authors they might have “out back” Apparently there isn’t an out back in the store and the nice lady told me that the only authors series pen they had was displayed.
The Verne series has been retired, so the odds of finding one in a store are slim to none.
Okay, so yes, I’ve been watching Ghostbusters on Hulu too much. The point here is to remind VTC Networks students not to go to lab this week. I won’t be there and you will be waiting around for a lab that won’t happen. Watch the forums for more information and Im working on another lecturecast this week. The book is a little light on NAT and Firewalls and I’d like to explore that more in the lecturecast.
And don’t forget, you’ve got less than a fortnight to complete the exam. Don’t get locked out.
I talk about routers a bit, I forget a thing in episode 7. We also work through DNS. Don’t forget to take the exam.
[podcast]http://www.skoda.net/podcast/cis2151-ep8.mp3[/podcast]
Layer 4, TCP and UDP. Read chapter 6
[podcast]http://www.skoda.net/podcast/cis2151-ep7.mp3[/podcast]
Grimlager has made it to level 70.
[quicktime width=”480″ height=”280″]http://www.skoda.net/wp-content/uploads/2008/10/grimlager-70.m4v[/quicktime]
