====== Static IP ======

**General Information**

Configure static IP, Mask, Gateway, and DNS.

**Checklist**
  * Distro(s): Debian or Enterprise Linux

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===== Configure Static Network Info =====

==== Debian/Ubuntu Systems ====
if possible, bring interface down first: ifdown eth0.

  * Edit /etc/network/interfaces<code bash>vim /etc/network/interfaces</code>

  * DHCP Setup Example (Default)<code bash>auto eth0
iface eth0 inet dhcp</code>

  * Static Setup Example<code bash>auto eth0
iface eth0 inet static
  address 192.168.0.100
  netmask 255.255.255.0
  gateway 192.168.0.254
  dns-nameservers 8.8.8.8 8.8.4.4</code>

  * Bring the interface up (if brought down at the start)<code bash>ifup eth0</code>

  * Otherwise, restart to fix nameserver conflicts between dhclient and static.<code bash>shutdown -r now</code>

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==== Redhat/CentOS Systems ====

Classic and NetworkManager methods of setting IP addresses for EL distros.

=== Classic (network) Method ===

Using config files and the network service.

  * Edit /etc/sysconfig/network-scripts/ifcfg-eth0<code bash>vim /etc/sysconfig/network-scripts/ifcfg-eth0</code>

  * DHCP Setup Example (Default)<code bash>DEVICE=eth0
ONBOOT=no (change to yes to have DHCP start automatically)
NM_CONTROLLED=yes
BOOTPROTO=dhcp</code>

  * Static Setup Example<code bash>DEVICE=eth0
ONBOOT=yes
NM_CONTROLLED=no
BOOTPROTO=static
IPADDR=192.168.0.101
NETMASK=255.255.255.0
GATEWAY=192.168.0.254</code>

  * Edit /etc/resolv.conf<code bash>vim /etc/resolv.conf

nameserver 8.8.8.8
nameserver 8.8.4.4</code>

  * Restart network service<code bash>/etc/init.d/network restart</code>

=== Network Manager ===

Using the NetworkManager service.

\\
Static IP/Gateway
  * Set a static IP on an existing interface (eth0)<code bash>nmcli con mod eth0 autoconnect yes ipv4.method manual ip4 192.168.1.50/24 gw4 192.168.1.254</code>
  * Apply settings<code bash>nmcli con up eth0</code>

\\
Static DNS
  * Set a static DNS entry<code bash>nmcli con mod eth0 ipv4.dns 1.1.1.1</code>
  * Apply changes<code bash>nmcli con up eth0</code>

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