Allow/deny ping on Linux server – iptables rules for icmp

Managing PING through iptables

Allow/deny ping on Linux server. PING – Packet InterNet Gopher, is a computer network administration utility used to test the reachability of a host on an Internet Protocol (IP) network and to measure the total round-trip time for messages sent from the originating host to a destination computer and back.

Blocking PING on server is helpful sometimes, if the server is continue to face any type of DDoS attack by using the PING feature. By using iptables we can simply stop the PING option to and from your server. Before starting this, you must have an idea about What is iptables in Linux?

We can call it is the basics of Firewall in Linux. Iptables is a rule based firewall system and is normally pre-installed on a Unix operating system which is controlling the incoming and outgoing packets. By-default the iptables is running without any rules, we can create, add, edit rules to it. You will get more details from the abouve link. In this article I am going to explain how we can alow/block PING in and out to a server. This would be more useful as you are Linux server admin.

We can manage it by the help of ‘iptables‘. The ‘ping‘ is using ICMP to communicate. We can simply manage the ‘icmp : Internet Controlled Message Protocol’ from iptables. Continue reading

How to Allow Pings (ICMP Echo Requests) Through Your Windows Firewall

When Windows Firewall is enabled with default settings, you can’t use the ping command from another device to see if your PC is alive. Here’s how to change that.

The ping command works by sending special packets known as Internet Control Message Protocol (ICMP) Echo Requests to a target device, and then waiting for that device to send back an ICMP Echo Reply packet. This not only lets you test whether a network-connected device is active, but it also measures the response time and displays that for you, as well. By default, Windows Firewall with Advanced Security blocks ICMP Echo Requests from the network. Sure, you could take the drastic step of disabling the firewall for testing purposes, but a simpler solution is just to create an exception that allows ICMP requests through the firewall. We’re going to show you how to do that both from the Command Prompt and the Windows Firewall with Advanced Security interface. (Note that, if you have an antivirus with a firewall or another type of third-party firewall program installed, you’ll need to open ports in that firewall instead of the built-in Windows Firewall.) Continue reading

How to Create New Active Directory Users with PowerShell

The easiest way to create a new user in an Active Directory domain is using the Active Directory Users and Computers MMC snap-in. However, what if you need to create multiple user accounts in bulk, or ADUC is not available for some reason? In this article, we explain several ways to create Active Directory user accounts with PowerShell using the New-ADUser cmdlet.

Create New User Accounts using the New-ADUser Cmdlet

So what is the PowerShell cmdlet used to create user objects? It’s the New-ADUser cmdlet, which is included in the Active Directory PowerShell module built into Microsoft Windows Server 2008R2/2012 and above. Therefore, the first thing we need to do is enable the AD module:

Import-Module ActiveDirectory

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Enable or Disable Windows Firewall from Command Prompt

There may come a time when you need to write a script or remotely connect to a PC and run a command to enable or disable the Windows firewall. For most IT environments, using Group Policy is the easiest way to configure the Windows Firewall on client computers.

It’s also the easiest way to add port exceptions for services such as HTTP, file sharing, software applications, and more. However, it’s also good to know how to configure the Windows Firewall from the command prompt just in case you have computers and servers that are not in Active Directory.

Manage Windows Firewall from Command Prompt

First, to see whether the Windows Firewall is enabled on a server or computer, type this command at the command prompt:

netsh advfirewall show allprofiles

Make sure you open an administrator command prompt (click on Start, type in CMD and then right-click on Command Prompt and choose Run as Administrator). You should get something similar to what is shown below:

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NIC Teaming in Windows Server 2012

Introduction

Windows Server 2012 has a number of great new features. One of the most welcome new features is the ability to create NIC teams. A NIC team is a collection of network interfaces (NICs) that work together as one. There are many benefits to building a NIC team. The main benefit is bandwidth aggregation. NIC teaming allows the bandwidth of every NIC in the team to be combined, thereby delivering more bandwidth than any single NIC in the team would be able to handle by itself.

Another noteworthy benefit to NIC teaming is redundancy. NIC teaming protects the server against NIC failures. If a NIC within a NIC team fails then the team is able to continue functioning in spite of the failure, but at a reduced capacity.

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How do I create a new server group in Server Manager on Windows Server 2012?

Server Manager is a great tool for performing tasks across multiple servers in your environment. By default, there is an All Servers group, but you can create your own groups and add servers manually to make management tasks easier. For example, you might want to create a group of servers that run a line-of-business application so that management tasks can be initiated simultaneously. Servers can be a member of more than one group.

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Monitor your computer and documents using the Group Policy

Group Policy allows you to audit or monitor the changes on your Windows computer. Using the Group Policy you can monitor who has logged on and when, who has opened a document, who has  created a new user account or changed a security policy.

To do so, type on secpol.msc in start search and hit Enter to open Local Security Policy.

Under Security settings in the left pane, expand Local Policies and then select Audit Policy.

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