Secure Router with IP access control lists (ACLs)

In this article we will look at very basic security feature of routers and L3 switches – Access Lists At the most basic level, an access list is a list of conditions that categorize packets and because of this, they can be really helpful when you need to exercise control over network traffic. One of…

Building CentOS 7 NetFlows Monitoring station with nfsen and nfdump

In this article we will look into setting up NetFlows monitoring station with open source tools. It is extremely important to keep track of what is happening on your network, who are the highest talkers and which users or programs accessing which resources. In our LAB example we will have Cisco Router on which we…

Which IPv4 private address class should I use ?

Private IP addresses are defined in RFC 1918. Theses addresses can be used on a private network, but they’re not routable through the Internet. By using private IP addresses, ISPs, corporations and home users can use some times only one public IP address to connect all internal systems to the internet. This is very economical…

Capturing packets with tcpdump

Tcpdump is a command line tool that is very useful during network troubleshooting. It will capture packets and display them on the screen or save them to a file. Installing tcpdump is very easy with yum. #yum install tcpdump In order to run tcpdump you will need to have root or sudo priviliges. Below are…

Deploy samba RedHat or CentOS 7

By definition samba is network file and print sharing service that is supported by most operating systems today. In this blog we will take a look at deploying samba server on REDHAT 7 system to share files with Windows 7 or 8 based client. The procedure will be same on CentOS, and most other distributions…

How to configure Interface Teaming with LACP using CentOS 7 and Redhat 7

Interface teaming is introduced in RHEL7 as an additional choice to implement fault tolerance and enhance throughput. It is widely considered more superior technique then Nic bonding and has much superior handling of packet flow then bonding. In this blog we will configure Nic teaming with LACP

Configure start up scripts for OVS on Centos and Red Hat

The RPM packages for Open vSwitch provide some integration with Red Hat’s network scripts. Using this integration is optional. To use the integration for a Open vSwitch bridge or interface named <name>, create or edit /etc/sysconfig/network-scripts/ifcfg-<name>. This is a shell script that consists of a series of VARIABLE=VALUE assignments. The following OVS-specific variable names are…

Choosing private IPv4 address range for internal network

If you are in IT consulting field many times you will be assigned task of creating IPv4 addressing for enterprise. Here we will pass on to you our experience of designing internal IP addressing using private IP range. On internal network we will use private IP range which is defined in RFC 1918.