Introduction to CS Network Henrik Thostrup Jensen September 15th - - PowerPoint PPT Presentation

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Introduction to CS Network Henrik Thostrup Jensen September 15th - - PowerPoint PPT Presentation

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Introduction to CS Network Henrik Thostrup Jensen September 15th 2006 1 About the Course Two Parts Today (lecture) & lab exercises Today Infrastructure, infrastructure, infrastructure Will not take four hours Lab

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Introduction to CS Network

Henrik Thostrup Jensen September 15th 2006

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SLIDE 2

About the Course

  • Two Parts
  • Today (lecture) & lab exercises
  • Today
  • Infrastructure, infrastructure, infrastructure
  • Will not take four hours
  • Lab Exercises
  • You define the content
  • Likely topics: L

AT

EX, Revision Control, Emacs

  • Important: Ask questions!
  • Slides are based on Gerd Behrmanns slides

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Lab Exercises

  • Hands-on exercises
  • Practical skills does not come from lectures
  • 3-4 Hours
  • Unix username required
  • Possible topics
  • Unix Shell (file & process management)
  • L

AT

EX

  • Revision Control
  • Emacs
  • Dates: 22/9, 29/9, 10/10 (Potentially more)
  • Fill out forms now!
  • Signup will be after I looked at the forms

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Group Room Equipment

  • One machine (usually)
  • Windows XP preinstalled
  • You can do pretty much what you want with this
  • Except take it apart or remove it from the room
  • Can sometimes get extra machine by asking

technician

  • Will usually be somewhat old
  • But not unusable

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SLIDE 5

Email & News

  • Two email servers
  • Outgoing (Sending): smtp.cs.aau.dk
  • Incoming (Reading): imap.cs.aau.dk
  • Also does POP3
  • Encryption is enforced (SSL / TLS)
  • News server:
  • NNTP: news.sunsite.dk
  • Not as much life as in the good old days
  • But still being used, CS Announce lives there
  • Requires account for external usage

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Recommended Email Clients

  • Webmail
  • http://www.cs.aau.dk/mail
  • Thunderbird
  • www.mozilla.org
  • /pack/thunderbird/bin/thunderbird
  • Pine

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Greylisting

  • Fighting the disease by killing the patient
  • Temporarely blocks mails
  • Dramatically reduces spam
  • Before: 50-90 spam mails pr day
  • After: 0-7 spam mails pr day
  • Delays mail, usually 30-120 minutes

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Greylisting

  • Whitelisting
  • Once accepted, the sending mailserver is whitelisted

for a period of time

  • Some mailservers are permenantly whitelisted
  • Disabling greylisting:
  • Create .cswhitelistme in home directory

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SLIDE 9

Mail filtering

  • SIEVE filters are used on the IMAP server
  • Can be created and edited in the web interface
  • Allows:
  • Sorting mail to different folders
  • Forwarding with rules
  • Block senders or subjects
  • Filter spam
  • Howto on CS network
  • One inbox equals chaos

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Home Directories

  • Home (student) directory: 300 MB Quota
  • Mount path: \\lfs0\username
  • Project directory: 500 MB Quota
  • Mount path: \\lfs0\groupname
  • Check your quota with quota
  • Group quota quota -g d201a

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Printers

  • You get 300 pages per semester
  • Color prints cost 10 pages!
  • Do not set your default printer to a color printer
  • Read CS Network for a printer list
  • Additional prints can be purchased
  • Print qouta lpac
  • Or your neighbour lpac -u user

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Printing

  • Windows
  • Print to \\cups\printer
  • You must login first - Enter the above in the run

dialog

  • Also works for other SMB clients, i.e., Samba
  • Unix Application Server
  • Check printer queue lpstat -d printer
  • Print lp -d printer doc.pdf
  • Cancel print job cancel printid

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PDF Printer

  • Special printer called pdf
  • Generates a PDF file in the cups-pdf directory in

your home directory

  • Good for transmogriffing stuff into PDF
  • Its free!

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Networks

  • CS: Application servers and labs, routable
  • A: Administration network (routers & printers)
  • E: Employee network, routable
  • S: Student/Supplementary network, internal network
  • This is where you connect your machine with a cable
  • W: Wireless network, isolated internal network
  • VPN: Virtual Private Network

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S Network

  • Private network - no direct connection to the internet
  • Access to proxy and application servers
  • Ports marked with a blue label
  • Other ports or usually disabled or locked
  • IPs are handed out by DHCP server
  • Proxy autodection is also enabled
  • Possible to request static IP assignment
  • Do NOT setup a DHCP server
  • Do NOT setup private wireless access points

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Wireless Network

  • Available most places at the university
  • At least in E and CISS part of the B building
  • SSID is AAU
  • Only few services is accessible
  • Web access via Java based VPN client
  • Which is sucky at best
  • Instead install the VPN client

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VPN

  • Provides secure access to CS network over insecure

networks

  • Cisco VPN client needed
  • VPN Client can be fetched from CS network
  • Supports Windows, Mac OS X, and Linux
  • Linux client is rather specific about kernel
  • Linux alternative: vpnc (google for it)

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Security

  • What is being done to ensure a secure environment
  • All mails are scanned for viruses
  • External access to resources is limited
  • External access is always encrypted
  • Access to physical network is limited
  • Logging

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Security

  • What you can do ensure a secure environment
  • Install and use virus software (esp. Windows)
  • Install and use a personal firewall (esp. Windows)
  • Keep your computer updated with latest patches
  • Do not run unnecessary services
  • Avoid Internet Explorer (use Firefox)
  • Avoid Outlook (use Thunderbird, etc.)
  • Use good passwords

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Security

  • Password
  • NOT a name or word found in any dictionary
  • NOT the previous with a digit before/after
  • Use nonsense words with mixed letters and digits
  • Or use the first/last letters in a sentence, title, song,

etc.

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OSs at the department

  • Sun Solaris 10
  • Red Hat Enterprise Linux 3 and 4
  • You can install Red Hat on your computer, due to
  • ur site license
  • Microsoft Windows XP
  • We have access to the MSDN Acedemic Allience

Program

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Application Servers

www.cs.aau.dk/cs network/equipment/servers.html A lot of software is installed on the servers

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Secure Shell

  • Provides secure login into Unix machines from other

machines

  • Including Windows
  • Can be used for:
  • Get shell access
  • Start graphical applications
  • Copy files (sftp)
  • Only way to access files from the outside
  • Windows SSH client
  • putty (google for it)
  • Java Applet http://www.cs.aau.dk/login/

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X11 Window System

  • The underlaying graphic mechanism in Unix
  • Also exist for Windows
  • Xwin client can be downloaded from CS Network
  • Also possible to use Cygwin (www.cygwin.com
  • Makes it possible to run programs on Unix servers,

with the window displayed at your computer

  • X11 via SSH
  • ssh -X host
  • ssh -Y host (if you get strange security warnings)
  • Sets up an X11 tunnel to the host

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Unix Directory Structure

  • Or: Where is all the stuff hidden
  • User home /user/username
  • Project directory /project/groupname
  • Programs
  • /pack/program
  • /pack/program-version
  • The usual places, i.e. in /bin/, /usr/bin, etc
  • Collections
  • /coll/LOCAL/bin
  • /coll/local/bin
  • /coll/new/bin
  • Paths should already be setup in your environment

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Changing your password

  • Solaris
  • passwd -r nis
  • Linux
  • yppasswd

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Your Own Web Page

  • www.cs.aau.dk/∼username
  • Store HTML files in: /user/name/.public html
  • Only serves static content (no CGI, PHP, etc)
  • www.cs.aau.dk/cs network/web/personal.html
  • For CGI, PHP, etc. use the development server
  • Can only be accesed from the inside
  • Possible to generate password for outside access
  • www.cs.aau.dk/cs network/web/develweb.html

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Text Processing

  • For reports, L

AT

EXis recommended

  • Read The not so Short Introduction to LaTeX
  • Link at the course homepage
  • Alternatives to L

AT

EX

  • . . .
  • What some use instead
  • OpenOffice, MS Office, StarOffice

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Processes

  • Processes are running programs
  • Many processes can run on the same machine
  • Many users can run processes on the same machine
  • You can run processes on other machines than the
  • ne you are sitting in front of
  • Processes can continue running after you have

logged out

  • You can run processes without being logged in

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Managing Processes

  • ps Process List
  • top Taple of Processes
  • kill pid Kill process with id pid
  • program& Run the program in the back ground
  • Will die when you log out
  • screen program Run the program in a screen
  • Will continue running after you logged out

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Where to find Documentation

  • CS Network:

http://www.cs.aau.dk/cs network/

  • Manual pages: man topic
  • Emacs: emacs -f info or C-h i in Emacs
  • Course web page:

www.cs.aau.dk/∼htj/csintro06.html

  • Fellow Students
  • www.google.com
  • The Junta

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Summary

  • Yes, the system is complex
  • Read the CS Network page
  • Sign up for the lab exercises
  • Questions?

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