Contents
Configure RHEL 5 Networking
Change Host Name
echo layer7 > /proc/sys/kernel/hostname
* See Redhat Linux Change Host Name
Setup Network Card: eth0
vi /etc/sysconfig/network-scripts/ifcfg-eth0
# VMware VMXNET3 Ethernet Controller DEVICE=eth0 BOOTPROTO=static # static IP address ONBOOT=yes HWADDR=00:0a:20:56:14:0b IPADDR=192.168.1.61 NETMASK=255.255.255.0 PEERDNS=no # This prevents /etc/resolv.conf from getting overwritten by /sbin/dhclient-script
Setup Networking
vi /etc/sysconfig/network
NETWORKING=yes HOSTNAME=layer7.mytest.local GATEWAY=192.168.1.1 NETWORKING_IPV6=no
Setup DNS
vi /etc/resolv.conf
search mytest.local nameserver 192.168.1.21
Setup /etc/nsswitch.conf
vi /etc/nsswitch.conf
hosts: files dns
Setup /etc/hosts File
* If nameserver is not setup, then we need to setup hosts file.
* If you have in /etc/nsswitch.conf file “hosts: files dns”, then /etc/hosts configuration overrides dns configuration.
vi /etc/hosts
192.168.1.61 layer7
Restart Networking
/etc/init.d/network restart
Issues
network restart: device eth0 seems not to be present
* Issue: When you clone or import a CentOS 6 virtual machine, for example by importing OVF template, you’ll notice that:
– eth0 is missing when you issue ifconfig command
– When you try to restart networking with network restart command, you get “device eth0 seems not to be present” error message
* Reason:
– CentOS 6 caches the original network card address in /etc/udev/rules.d/70-persistent-net.rules file
– When Centos first starts, it sees the conflicts and renames eth0 to eth1
* To fix, remove the cache file and reboot
rm /etc/udev/rules.d/70-persistent-net.rules reboot