BIND – Berkeley Internet Name Daemon (BIND) is the reference implementation of the Domain Name System (DNS) protocols. The software consists, most prominently, of the DNS Server component, called named. In addition the suite contains various administration tools, and a DNS resolver interface library. It is the most widely used DNS software.
It is a recommended practice that you have two nameservers. They will act as a primary and a secondary servers in case one fails.
The steps below outlines the installation and configuration of BIND using Webmin on a CentOS 6 server.
Linux bonding driver provides a method to aggregate multiple network interface cards into a single logical / teamed / bonded interface. The behaviour depends on the mode of the bonding that we choose, but generally speaking the modes provide either hot standby or load balancing.
Bond Interfaces can be very useful if you want to divide the entire network using VLANs and allow per VLAN traffic with the view to have reliable and redundant network connectivity. Here, I am trying to provide a procedure to create a bonded interface under CentOS 6.4. This is not a new concept but it provides a tested procedure that I have used to create my setup which is named as “The Matrix” – The Matrix
CREATING A BONDED INTERFACE
In order for us to have a reliable network and have the ability to use VLAN’s a bonded interface is created so that the load can be split on both the interfaces with the flexibility of using more than one network
To separate the traffic the use VLANs and bridge interfaces is common. For the separation, we used VLANs and the bridge interfaces that would be connecting to the virtual hosts would not be connected to the physical interfaces, but instead would be connected to the virtual interfaces that we would be configuring as part of the Linux VLAN configuration
Based on the article at the following location, I decided to put together the following configuration which will be used for the Controller and the Compute Nodes
Setting up the /etc/sysconfig/network configuration file
Add / Change the following information
Go to /etc/sysconfig/network-scripts
Create interface – bond0
Change interface – eth0
Change Interface – eth1
Modify the file – /etc/modprobe.d/bonding.conf
alias bond0 bonding
options bond0 mode=5 miimon=100 arp_interval=100
Since I was using VLANs, I will now create the VLAN interface on top of bond0, bond0.140 and bond0.180 pointing to the appropriate bridge interfaces
Once the networking was configured, applied static routes to the interfaces did not work and I was unable to ping both the bonded interfaces. The interface that I was able to ping was the one that came up first. Following was the output of the routing table
After doing some research, I concluded that I can use the Linux kernel as routers and as many routers do they can route packets from one network to the other.
In my network I am using two VLAN <vlan_id> and <vlan_id>, so the following changes were made in order to ping both the networks
Look for – net.ipv4.conf.default.rp_filter
Change the value from 1 to 2. And if this value is not available then add the value.
Finally I got this working and all the tests for redundancy is finally completed.