Easy Remote Administration

Transcription

1 1 What 2 Why DHCP is Linux? Linux is a free Unix-type operating system originally created by Linus Torvalds with the assistance of developers around the world. Developed under the GNU General Public License, the source code for Linux is freely available to everyone. Many companies and individuals distribute Linux. Each version is called a distribution and each has its own unique strengths. Some are updated faster than others. Some have better admin tools or hardware support built in. Some are geared towards server installations and some toward desktop usage. Linux? VPN DHCP Server Samba Server DNS Server Web Server Proxy Firewall Mail Filter Network Services Future: and Accelerated Reader There are many ways to manage a Linux server or workstation: By manually modifying configuration files Using GUI tools that come with the distribution you are using Access to a Linux box remotely can be obtained by using an SSH client (such as Putty) and connecting to the server's SSHd service. also allows remote access through an HTTP or HTTPS connection. Setup of a DHCP server to assign addresses to your workstations is much simpler than tracking the assignments by hand. to setup and very reliable. Dynamic DNS support. BootP support. Multiple subnets and supernets. 8 Samba Samba is file and printer sharing software that allows clients to connect to a Linux server as if it were an NT/Windows 2000 Server. You can specify whether to use domain logins or workgroup authentication. Authentication can come from a password file, LDAP server, or database server. Shares are setup on the server and access granted by user and/or group. Printers are by default automatically shared with all clients and you can store the driver on the server for easier installation to the workstation. No per user cost for clients to connect.

2 9 Proxy 10 Proxy 11 Content 12 VPN 13 VPN 14 DNS 15 Web Cache Squid is an Internet proxy server that can be used to proxy HTTP, HTTPS, FTP and Gopher access to the Internet for client workstations. By enabling caching on the proxy server, bandwidth to the Internet can be saved by having the data retrieved from a local cache on the server and sent to the client. Up to 60% of your users' web access would typically be retrieved from cache instead of the Internet. This results in less bandwidth usage and a faster response time to the client. There are modules available for squid to allow you to authenticate users before they access the Internet. The authentication can come from Windows servers, NetWare servers, a database, LDAP or a text file. Cache Proxy setup at Etowah County If data is not found on local school proxy, then master proxy at BoE is checked. If not there then data is fetched from the Internet. Filtering SquidGuard is a content filtering product that can be added to the caching server to stop users from going to domains listed in a database. You can also stop users from going to sites that have certain words in the URL - like 'sex', 'ad', etc. Dan's Guardian is a filtering product that allows you to filter pages based on keywords in the web page. If the page has profane language or words in a list that you specify, it won't be allowed to get to the client. Site-to-Site Setup VPN tunnels from 3 remote school sites back to the Board of Education. Provided filtered web access and the ability to manage the remote schools at faster than dial-in speeds. Tunnel was both encrypted for security and compressed to save on bandwidth. If tunnel was interrupted because of a circuit being down, it would try and reconnect every 5 seconds until successful. Site-to-Site Setup There are many choices for DNS servers available on the Linux platform: BIND DJBDNS MARA DJBDNS has several nice features: Very secure. The ability to give out different addresses depending on requesters location. Most Linux distributions include the Apache web server. 62% of all web servers on the Internet run Apache - far more than any other server. Apache is the most popular. Zope has built in scripting and GUI access management. AOL Web Server. If only static pages are to be served, the Linux kernel has a built-in web server that is twice as fast as the alternatives. 16 Apache There are many modules available to enhance the functionality of Apache. mod_perl mod_php mod_rewrite mod_auth_ldap And many, many more.

3 17 Firewall IPTables is the dominant firewalling code in use. The basic code supports NAT, PAT, and stateful inspection. Additional functionality that can be added through the Patch-O-Matic system available on netfilter.org and 18 Mail includes: Quota support - limit number of bytes to a host during a certain period Time restrictions - only allow Internet access for certain hosts or networks during certain time periods or days. Conditions - allow routing of packets to alternative hosts if primary host is down Command execution - execute commands if packet matches a certain criteria Linux makes an excellent low cost mail server. By combining the basic SMTP server with POP3, IMAP and webmail services you can put together a system with most of the features found in expensive groupware products. Sendmail has been the most popular SMTP server but Postfix and Qmail are rapidly rising in popularity because of their enhanced security. Number of vulnerabilities by product listed on : Postfix has only 1. Sendmail has 45. Qmail has 3. Exchange has 39. GroupWise has Webmail 20 Mail 21 Mail Popper Filtering By all accounts, SPAM takes up between 35% and 65% of the traffic on the Internet. Even if you have a commercial groupware or system, by frontending your system with a Linux mail server running anti-spam software such as SpamAssassin you can remove or mark your spam before it reaches the end user. The mail can also be filtered for viruses and text content at the same time. Filtering Many of the open source products can be combined so that spam filtering, attachment filtering and virus scanning can all be applied at the same time to Monitoring Nagios (formerly NetSaint) is an excellent choice for monitoring the status of your network devices. Monitoring of network services (SMTP, POP3, HTTP, NNTP, PING, etc.) Monitoring of host resources (processor load, disk and memory usage, running processes, log files, etc.) Monitoring of environmental factors such as temperature Simple plugin design that allows users to easily develop their own host and service checks Ability to define network host hierarchy, allowing detection of and distinction between hosts that are down and those that are unreachable Contact notifications when service or host problems occur and get resolved (via , pager, or other user-defined method) 23 Monitoring Nagios detail page showing up/down status of hosts. 24 Monitoring Nagios network overview map

4 25 Database 26 Workstation 27 Nessus There are many commercial and open source database servers available for Linux. Commercial databases include: IBM's DB2 Oracle Open Source servers include: MySQL PostgreSQL msql Data Recovery Using bootable Linux 'Live CD's you can retrieve data from a crashed workstation without opening the case. Boot with the CD. Mount the local partition and the server share or volume. Copy the data. Retrieve data from FAT16/32 and NTFS partitions. Linux 'Live CD' distributions: Knoppix Gentoo DemoLinux Security Scanner The "Nessus" Project aims to provide to the internet community a free, powerful, up-to-date and easy to use remote security scanner. 28 Nessus A security scanner is a software which will audit remotely a given network and determine whether bad guys (aka 'crackers') may break into it, or misuse it in some way. Unlike many other security scanners, Nessus does not take anything for granted. That is, it will not consider that a given service is running on a fixed port - that is, if you run your web server on port 1234, Nessus will detect it and test its security. It will not make its security tests regarding the version number of the remote services, but will really attempt to exploit the vulnerability. Security Scanner 29 Linux is an effective platform for teaching programming skills. There are a multitude of programming languages 30 available at little or no cost. C++ C Perl PHP Ruby Python Pascal And many more IDEs There are several very good Integrated Development Environments available for Linux: Kdevelop is available for C and C++ programming. GAMBAS (a BASIC programming language) has a good IDE that is actually written in GAMBAS itself. WxWorkshop for Java and C++ development. Kylix for Borland's Object Oriented Pascal development.

5 31 IDEs Kdevelop 32 IDEs GAMBAS 33 is an application that allows you to run Windows programs in Linux. actually stands for Wine Is Not an Emulator. We are evaluating it in order to determine whether it will run some of the standard classroom apps to remove the requirement of a Windows license on the classroom workstations. We are in the process of testing Accelerated Reader AR Accelerated Reader - AR Accelerated Reader - AR Accelerated Reader allows you to open and track trouble tickets. With the addition of the KBShare knowledge base program, managing your todo list becomes very easy. features: Security access based on login. sent to person the ticket is assigned to. sent when reassigning a ticket. Multiple followups added to tickets until tickets are closed. Report by open tickets, closed tickets and location. Written in PHP and easily modifiable - add your own report types or features Knowledge 42 Knowledge Open a ticket Ticket view Report view Management KBShare is a web based program modeled after Novell's support TIDs (Technical Information Documents) that allows you to store problems and their solutions in an online database and access them when needed. Data can be searched for by site/school and by keywords or phrases. The use of boolean searching helps to retrieve the exact data you need quickly. Firewall AND nat Windows NOT xp Cisco AND s0 Management KBShare - search page

6 43 Knowledge Management KBShare - results page KHangman is the classical hangman game. KLettres aims to help to learn the alphabet and then to read some syllables in different languages. KMessedWords is a simple mind-training game, in which you have to "figure out" the word that has been given in the program. KVerbos is an application specially designed to study Spanish verb forms. KVocTrain is a vocabulary trainer. Like most of the other vocabulary trainers it uses the "flash card" approach. Kiten is a Japanese reference/learning tool. KPercentage is a small math application that will help pupils to improve their skills in calculating percentages. KmPlot is a mathematical function plotter. FlashKard is a vocabulary studying tool for learning languages or termninology. KTouch is a program for learning touch typing. KStars is a Desktop Planetarium program. Kalzium is an application which will show you some information about the periodic system of the elements. KEduca is an educational project to enable the creation and revision of form-based tests and exams. Kstars Kstars Kalzium 48 is a multi-platform office productivity suite. It includes the key desktop applications, such as a word processor, spreadsheet, presentation manager, and drawing program, with a user interface and feature set similar to other office suites. Sophisticated and flexible, also works transparently with a variety of file formats, including those of Microsoft Office. It is fully open sourced and available for Linux and Windows platforms. This presentation was done in 's Impress software. 49 Writer 50 Calc Linux Impress Links Linux Online - Sourceforge (software index) - Freshmeat (software index) - Linux Today (news) - Linux for Kids (school software) - Seul/Edu Application Index - Educa (educational software) - Vulnerability Search - Distribution Watch - VTUN (VPN) -