How to Deny Responses to Ping Requests Using iptables

Sometimes you need to “hide” your server by denying responses to ping requests. This way your server will look like it is offline. ping <server_ip> will return connection timeout. There is a short linux command that will allow to do this using iptables. Here it is: iptables -t filter -A INPUT -p icmp -j REJECT This will ignore… Read More »

How to Set the Correct Hostname for Directadmin

Often after initial Directadmin setup, made by your server provider, you keep getting the following message: Subject: This is e-mail notification to warn you that your hostname is setup improperly on your system. You keep getting this e-mail daily until you do something with your hostname. It’s quite a strange thing that hostname isn’t set up during main… Read More »

How to Add an IP to a Linux Server

When you decide to rent a dedicated server, you almost in all cases get more than one IP address. This is used for DNS management and other stuff that is related to unique IPs. For example, you want to assign a dedicated IP to one of your site. Let’s take we don’t have any panel installed (like CPanel,… Read More »

Working With E-mail Using Telnet

We often send and receive e-mails. Thanks to spammers, we do more receive mail than send it, but it is not the glue. We usually use e-mail clients that are negotiating with POP3 (IMAP) and SMTP servers. Though IMAP is more secure, POP3 is much simpler and you can find it anywhere. But… let’s imagine your e-mail client… Read More »

How to Copy Files Between Servers via SSH Using Midnight Commander

If you are a system administrator, you should often need to copy files between servers. I think that the most useful tools for this is Midnight Commander (mc). I will show you how to establish a SSH connection to another server in this post. First of all let’s start midnight commander from command line by typing mc. If… Read More »

Finding Big Files With Linux Find Command

Finding files is a very common practice for all operating systems. I don’t think this is a trick. but it’ll be very helpful for newbies to know the exact command to find big files, especially when you don’t have enough space on your machine and want to know which files take most of your space. find / -size… Read More »

How to Reload a Page Only Once Using Javascript

Here is a small piece of code that allows to reload a page only once. This is necessary to prevent some data being cached and this is the only solution I found good for my needs. Meta tag nocache did not save me, and meta tag refresh does not allow to refresh the page only once. So here… Read More »

Adding Google Adsense Code Between Topics in phpBB

You can often see it even on popular forums. Google Adsense or any other ad code is inserted between posts or looks like a usual post. How do they do that? I will show you how to add Adsense code after first post and I hope you will be able to figure out how to do it to… Read More »