CentOS BIND DNS Not Responding To DNS Queries
KB ID 0000906 Problem While moving my DNS records from my old hosting company, I finally got round to pointing my domain name server records at my own server. I then saw my web traffic nose dive! Some troubleshooting steps later I realised I could not connect to my server on TCP port 53 (use an online port scanner to test yours). Solution Allow Access to DNS BIND From Remote Clients 1. Firstly let’s make sure that the firewall...
CentOS – Setup the iptables Firewall
KB ID 0000938 Problem I was a little perturbed to find out the firewall on my CentOS web server was wide open today. My server setup notes yielded no clues, so it was time to put my ‘Linux Head’ on and fix it. Solution 1. Connect to the server via console or SSH. As I’m going to change the iptables config file lets back it up (always assume you are going to smash something!) cp /etc/sysconfig/iptables iptables.bak 2....
CentOS 7 – No Network Connection
KB ID 0001047 Problem A while ago I spun up a CentOS server in VMware Workstation, and I could not get it connected to the network, I was in a bit of a hurry, so I blew it away and just built a new server with CentOS 6. This week I’ve been using VirtualBox and spun up a new CentOS 7 server and had the same problem. Solution 1. Quite why CentOS 7 does this I’m not sure, My NIC is called enp0s3 (run ‘ip addr’ to...
CentOS 7 – Ifconfig Command Not Found
KB ID 0001048 Problem Although not my strongest subject, I know enough to get by in Linux, so I was a little put out when I tried to run ifconfig, only to be told it could not be found. On an ‘out of the box’ install you are supposed to use ‘ip addr’ instead. Solution To Install Ifconfig 1. Run either of the following; yum provides ifconfig or yum whatprovides ifconfig And you should see a net-tools package....
Brocade 300 SAN Switch – Setup and Configure
KB ID 0000593 Problem I got a warning from a colleague that these switches, were no longer ‘Open’. i.e. You can no longer just plug them in, connect all your SAN devices and it will work. That’s how they used to work, so someone has decided to have then ‘Not Work’ out of the box (Nice one, well done). Solution Rack fitting the Brocade 300 SAN Switch 1. Each mounting rail is in three pieces (2 long pieces...