Go back to fronty page View most popular entries View latest additions Submit tutorials to UnixTutorials.info
UnixTutorials logo

Search results for Hardening OpenBSD Internet Servers

Ubuntu

How to install Opera Web Browser in Ubuntu including flash,Java Plugins

Post date: October 18, 2009, 19:10 Category: Software Views: 3289 Comments
Tutorial quote: Opera is a web browser and internet suite developed by the Opera Software company. The browser handles common
Internet-related tasks such as displaying websites, sending and receiving e-mail messages, managing contacts, IRC
online chatting, downloading files via BitTorrent, and reading web feeds. Opera is offered free of charge for
personal computers and mobile phones, but for other devices it must be paid for.
Gentoo

Tunneling the hard way: using slirp, pppd and socat

Post date: January 29, 2006, 13:01 Category: Network Views: 11463 Comments
Tutorial quote: Every now and then you might come across a "bad" ISP. The one I have at home for example is dropping UDP packets ever so often when I try to play online games -- and it tends to drop random packets while I try to log onto a gameserver too which makes a certain game I like to play crash during the loading phase so it can't recover. I also heard of other ISPs blocking certain ports on external servers -- universities for example seem to like blocking p2p network ports and the school i was attending till last august blocked everything but port 80 for http -- including ftp which made even on-topic "research" a pita at times.
Usually there's three ways of working around this problem if "giving up" is not an option to you: a) change your ISP, b) use ssh to redirect ports, c) connect to an external VPN to route for you. a) can be tricky -- it's impossible if you're sharing the link with your parents and they insist on their email addresses or in the university/workplace/school scenario. b) will only work with single port/host combinations and for c) you will need a full-fledged rootbox idling around on the internet -- which tend to be expensive and "virtual servers" might not work because those often don't include tun/tap devices and/or kernel-level ppp support if you rent them and in case you rented them you probably can't fiddle around with its kernel to enable it (that was my problem at least). If any of this rings a bell to you, read on and discover method d)
Linux

Upstream Provider Woes? Point the Ping of Blame

Post date: April 14, 2005, 12:04 Category: Network Views: 2443 Comments
Tutorial quote: Your users are complaining that "the Internet is, like, all slow." Users are always complaining, but you're seeing a lot of timeouts when you check mail, surf the Web, or try to log in for remote administration. Or even worse, latency is so bad that you keep getting killed all to heck in your favorite gory violent online multi-player game, so you know there is a problem. But there a lot of potential bottlenecks between your PC and the outside world, like your Internet gateway, proxy server, firewall, Internet service provider, and so forth, so where do you begin?

One of the best and most versatile network tools you can have is a notebook PC running Linux. This lets you plug in anywhere to run tests and find out what is going on. Make it a nothing-to-lose box--don't keep data on it so you can wipe and reinstall the operating system as necessary, because you want to be able to run tests outside of firewalls. Don't run any services. You can put a minimal iptables firewall on it, as there is no point in being totally exposed, but keep it simple. (Use MondoRescue to make a system snapshot for fast restores.)
Debian

Installing A Web, Email, MySQL DB Cluster (Mirror) On Debian 5 With ISPConfig 3

Post date: August 11, 2010, 23:08 Category: Installing Views: 3586 Comments
Tutorial quote: This tutorial describes the installation of a clustered web, email, database and DNS server to be used for redundancy, high availability and load balancing on Debian 5 with the ISPConfig 3 control panel. GlusterFS will be used to mirror the data between the servers and ISPConfig for mirroring the configuration files. I will use a setup of two servers here for demonstration purposes but the setup can scale to a higher number of servers with only minor modifications in the GlusterFS configuration files.
Unix+clones

Mysql Cluster: Two webserver setup (three servers required for true redundancy)

Post date: July 11, 2005, 12:07 Category: Network Views: 3011 Comments
Tutorial quote: This HOWTO was designed for a classic setup of two servers behind a loadbalancer. The aim is to have true redundancy - either server can be unplugged and yet the site will remain up.
Linux

How To Migrate Mailboxes Between IMAP Servers With IMAP TOOLS

Post date: October 27, 2011, 08:10 Category: Miscellaneous Views: 19581 Comments
Tutorial quote: This guide explains how you can migrate mailboxes between IMAP servers with IMAP TOOLS. IMAP TOOLS is a collection of Perl scripts that allow you to do various tasks with IMAP servers and also POP3 servers. In this article I will focus on the scripts imapcopy.pl (copies messages and mailboxes from one IMAP server to another) and pop3toimap.pl (copies POP3 messages to an IMAP server). Both scripts support SSL. If you specify port 993 (995 for POP3) then an SSL connection is initiated. If the port number is 143 (110 for POP3) then it will try a non-SSL connection. With any other value the port will be tested to see if it supports SSL. If so, SSL will be used to make the connection; otherwise a non-SSL connection will be made.
OpenSUSE

Perfect Paper Passwords - One Time Password System (OpenSuse)

Post date: April 20, 2009, 09:04 Category: Security Views: 3634 Comments
Tutorial quote: Almost without exception, today's Internet users prove their identity online using a fixed account name and password. In the past, this simple system provided sufficient security. But with the growing popularity of online banking and eCommerce, the value of stealing online identities has skyrocketed. And the increasing presence and "spyware" and "malware" on innocent users' computers means that users can be "watched" while logging onto their banking and other eCommerce sites. Once their logon credentials have been "captured" and stolen, Internet criminals can easily assume their identity.
Unix+clones

Comparing MySQL performance

Post date: April 12, 2005, 07:04 Category: Benchmarks Views: 3454 Comments
Tutorial quote: With the introduction of the 2.6 Linux kernel, FreeBSD-5-STABLE, Solaris 10, and now NetBSD 2.0, you might be wondering which of them offers superior database performance. In my previous article, I discussed the tools I chose to test these venerable operating systems and the methodology by which they were tested. The result is this MySQL performance comparison between OpenBSD 3.6; NetBSD 2.0; FreeBSD 5.3 and 4.10; Solaris Express (build 69); and Linux 2.4 and 2.6 (Gentoo-based). Read on for the results.
Debian

Setting Up A Highly Available NFS Server

Post date: April 1, 2006, 05:04 Category: Network Views: 6349 Comments
Tutorial quote: In this tutorial I will describe how to set up a highly available NFS server that can be used as storage solution for other high-availability services like, for example, a cluster of web servers that are being loadbalanced. If you have a web server cluster with two or more nodes that serve the same web site(s), than these nodes must access the same pool of data so that every node serves the same data, no matter if the loadbalancer directs the user to node 1 or node n. This can be achieved with an NFS share on an NFS server that all web server nodes (the NFS clients) can access.

As we do not want the NFS server to become another "Single Point of Failure", we have to make it highly available. In fact, in this tutorial I will create two NFS servers that mirror their data to each other in realtime using DRBD and that monitor each other using heartbeat, and if one NFS server fails, the other takes over silently. To the outside (e.g. the web server nodes) these two NFS servers will appear as a single NFS server.

In this setup I will use Debian Sarge (3.1) for the two NFS servers as well as for the NFS client (which represents a node of the web server cluster).
Linux

Block Spammers/Hackers With mod_defensible On Apache2

Post date: December 5, 2008, 12:12 Category: Security Views: 2968 Comments
Tutorial quote: mod_defensible is an Apache 2.x module intended to block spammers using DNSBL servers.

It will look at the client IP and check it in one or several DNSBL servers and return
a 403 Forbidden page to the client.
Web-based applications and online marketing solutions - LumoLink