config network name

Configure each host in the cluster as follows to ensure that all members can communicate with each other:

Set the hostname to a unique name (not localhost).
```
sudo hostnamectl set-hostname foo-1.example.com
```
Edit /etc/hosts with the IP address and fully qualified domain name (FQDN) of each host in the cluster. You can add the unqualified name as well.
```
1.1.1.1  foo-1.example.com  foo-1
2.2.2.2  foo-2.example.com  foo-2
3.3.3.3  foo-3.example.com  foo-3
4.4.4.4  foo-4.example.com  foo-4
```
Important:
- The canonical name of each host in /etc/hosts must be the FQDN (for example myhost-1.example.com), not the unqualified hostname (for example myhost-1). The canonical name is the first entry after the IP address.
- Do not use aliases, either in /etc/hosts or in configuring DNS.
- Unqualified hostnames (short names) must be unique in a Cloudera Manager instance. For example, you cannot have both host01.example.com and host01.standby.example.com managed by the same Cloudera Manager Server.
Edit /etc/sysconfig/network with the FQDN of this host only:
```
HOSTNAME=foo-1.example.com
```
Verify that each host consistently identifies to the network:
1. Run uname -a and check that the hostname matches the output of the hostname command.
2. Run /sbin/ifconfig and note the value of inet addr in the eth0 (or bond0) entry, for example:
```
eth0      Link encap:Ethernet  HWaddr 00:0C:29:A4:E8:97  
          inet addr:172.29.82.176  Bcast:172.29.87.255  Mask:255.255.248.0
...
```
3. Run host -v -t A $(hostname) and verify that the output matches the hostname command.
  The IP address should be the same as reported by ifconfig for eth0 (or bond0):
```
Trying "foo-1.example.com"
...
;; ANSWER SECTION:
foo-1.example.com. 60 IN
A
172.29.82.176
```