To verify that the current networking configuration is valid and correct:
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To verify the format and content of /etc/hosts , run the command:
[root@server root]# cat /etc/hosts
Here is an example of the hosts file:
127.0.0.1 localhost.localdomain localhost
192.168.1.10 server.domain.com server
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To verify the contents of /etc/sysconfig/network , run the command:
[root@server root]# cat /etc/sysconfig/network
Confirm that the proper values for your environment exist for the fully qualified hostname and gateway. Consult your network administrator if you are unsure of the proper values.
Here is an example of the network file:
NETWORKING=yes
HOSTNAME=server.domain.com
GATEWAY=192.168.1.1
GATEWAYDEV=vswif0
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To verify that /etc/sysconfig/network-scripts/ifcfg-vswif0 has the correct settings for IP address (IPADDR), subnet mask (NETMASK), and network (NETWORK), run the command:
[root@server root]# cat /etc/sysconfig/network-scripts/ifcfg-vswif0
Consult your network administrator if you are unsure of the correct settings.
Here is an example of the ifcfg-vswif0 file:
DEVICE=vswif0
BOOTPROTO=static
BROADCAST=192.168.1.255
IPADDR=192.168.1.10
NETMASK=255.255.255.0
NETWORK=192.168.1.0
ONBOOT=yes
PORTGROUP="Service Console"
MACADDR=##:##:##:##:##:##
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To display the routing table, run the command:
[root@server root]# route –n
The output looks similar to:
Kernel IP routing table
Destination Gateway Genmask Flags Metric Ref Use Iface
192.168.1.0 0.0.0.0 255.255.255.0 U 0 0 0 vswif0
169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 vswif0
0.0.0.0 192.168.1.1 0.0.0.0 UG 0 0 0 vswif0
Ensure that the second column of the row flagged with UG matches the gateway address for your environment.
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To verify that the DNS information in /etc/resolv.conf is correct for your environment, run the command:
[root@server root]# cat /etc/resolv.conf
Here is an example of the resolv.conf file:
search domain.com
nameserver 192.168.1.2
nameserver 192.168.1.3
Note: By default, up to three nameservers can be added to resolv.conf. The compile time parameter MAXNS defines how many nameservers can be used.
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Note: Changes to the network and ifcfg-vswif0 files require a restart of the network service. To restart the network service, run the following command and press Enter:
[root@server root]# service network restart