openstack-manuals/doc/install-guide-rst/source/basics-networking-nova.rst

Legacy networking (nova-network)

The example architecture with legacy networking (nova-network) requires a controller node and at least one compute node. The controller node contains one network interface on the management network. The compute node contains one network interface on the management network and one on the external network.

The example architecture assumes use of the following networks:

• Management on 10.0.0.0/24 with gateway 10.0.0.1

  Note

  This network requires a gateway to provide Internet access to all nodes for administrative purposes such as package installation, security updates, DNS, and Network Time Protocol (NTP).

• External on 203.0.113.0/24 with gateway 203.0.113.1

  Note

  This network requires a gateway to provide Internet access to instances in your OpenStack environment.

You can modify these ranges and gateways to work with your particular network infrastructure.

Note

Network interface names vary by distribution. Traditionally, interfaces use "eth" followed by a sequential number. To cover all variations, this guide simply refers to the first interface as the interface with the lowest number and the second interface as the interface with the highest number.

Unless you intend to use the exact configuration provided in this example architecture, you must modify the networks in this procedure to match your environment. Also, each node must resolve the other nodes by name in addition to IP address. For example, the controller name must resolve to 10.0.0.11, the IP address of the management interface on the controller node.

Warning

Reconfiguring network interfaces will interrupt network connectivity. We recommend using a local terminal session for these procedures.

Controller node

To configure networking:

1. Configure the first interface as the management interface:

   IP address: 10.0.0.11

   Network mask: 255.255.255.0 (or /24)

   Default gateway: 10.0.0.1

2. Reboot the system to activate the changes.

To configure name resolution:

1. Set the hostname of the node to controller.

2. Edit the /etc/hosts file to contain the following:

   # controller
   10.0.0.11       controller
   
   # compute1
   10.0.0.31       compute1

   Warning

   Some distributions add an extraneous entry in the /etc/hosts file that resolves the actual hostname to another loopback IP address such as 127.0.1.1. You must comment out or remove this entry to prevent name resolution problems.

Compute node

To configure networking:

1. Configure the first interface as the management interface:

   IP address: 10.0.0.31

   Network mask: 255.255.255.0 (or /24)

   Default gateway: 10.0.0.1

   Note

   Additional compute nodes should use 10.0.0.32, 10.0.0.33, and so on.

2. The external interface uses a special configuration without an IP address assigned to it. Configure the second interface as the external interface:

   Replace INTERFACE_NAME with the actual interface name. For example, eth1 or ens224.

   ubuntu or debian

   1. Edit the /etc/network/interfaces file to contain the following:

      # The external network interface
      auto INTERFACE_NAME
      iface  INTERFACE_NAME inet manual
      up ip link set dev $IFACE up
      down ip link set dev $IFACE down

   rdo

   1. Edit the /etc/sysconfig/network-scripts/ifcfg-INTERFACE_NAME file to contain the following:

      Do not change the HWADDR and UUID keys.

      DEVICE=INTERFACE_NAME
      TYPE=Ethernet
      ONBOOT="yes"
      BOOTPROTO="none"

   obs

   1. Edit the /etc/sysconfig/network/ifcfg-INTERFACE_NAME file to contain the following:

      STARTMODE='auto'
      BOOTPROTO='static'

3. Reboot the system to activate the changes.

To configure name resolution:

1. Set the hostname of the node to compute1.

2. Edit the /etc/hosts file to contain the following:

   # compute1
   10.0.0.31       compute1
   
   # controller
   10.0.0.11       controller

   Warning

   Some distributions add an extraneous entry in the /etc/hosts file that resolves the actual hostname to another loopback IP address such as 127.0.1.1. You must comment out or remove this entry to prevent name resolution problems.

Verify connectivity

We recommend that you verify network connectivity to the Internet and among the nodes before proceeding further.

1. From the controller node, ping a site on the Internet:

   # ping -c 4 openstack.org
   PING openstack.org (174.143.194.225) 56(84) bytes of data.
   64 bytes from 174.143.194.225: icmp_seq=1 ttl=54 time=18.3 ms
   64 bytes from 174.143.194.225: icmp_seq=2 ttl=54 time=17.5 ms
   64 bytes from 174.143.194.225: icmp_seq=3 ttl=54 time=17.5 ms
   64 bytes from 174.143.194.225: icmp_seq=4 ttl=54 time=17.4 ms
   
   --- openstack.org ping statistics ---
   4 packets transmitted, 4 received, 0% packet loss, time 3022ms
   rtt min/avg/max/mdev = 17.489/17.715/18.346/0.364 ms

2. From the controller node, ping the management interface on the compute node:

   # ping -c 4 compute1
   PING compute1 (10.0.0.31) 56(84) bytes of data.
   64 bytes from compute1 (10.0.0.31): icmp_seq=1 ttl=64 time=0.263 ms
   64 bytes from compute1 (10.0.0.31): icmp_seq=2 ttl=64 time=0.202 ms
   64 bytes from compute1 (10.0.0.31): icmp_seq=3 ttl=64 time=0.203 ms
   64 bytes from compute1 (10.0.0.31): icmp_seq=4 ttl=64 time=0.202 ms
   
   --- compute1 ping statistics ---
   4 packets transmitted, 4 received, 0% packet loss, time 3000ms
   rtt min/avg/max/mdev = 0.202/0.217/0.263/0.030 ms

3. From the compute node, ping a site on the Internet:

   # ping -c 4 openstack.org
   PING openstack.org (174.143.194.225) 56(84) bytes of data.
   64 bytes from 174.143.194.225: icmp_seq=1 ttl=54 time=18.3 ms
   64 bytes from 174.143.194.225: icmp_seq=2 ttl=54 time=17.5 ms
   64 bytes from 174.143.194.225: icmp_seq=3 ttl=54 time=17.5 ms
   64 bytes from 174.143.194.225: icmp_seq=4 ttl=54 time=17.4 ms
   
   --- openstack.org ping statistics ---
   4 packets transmitted, 4 received, 0% packet loss, time 3022ms
   rtt min/avg/max/mdev = 17.489/17.715/18.346/0.364 ms

4. From the compute node, ping the management interface on the controller node:

   # ping -c 4 controller
   PING controller (10.0.0.11) 56(84) bytes of data.
   64 bytes from controller (10.0.0.11): icmp_seq=1 ttl=64 time=0.263 ms
   64 bytes from controller (10.0.0.11): icmp_seq=2 ttl=64 time=0.202 ms
   64 bytes from controller (10.0.0.11): icmp_seq=3 ttl=64 time=0.203 ms
   64 bytes from controller (10.0.0.11): icmp_seq=4 ttl=64 time=0.202 ms
   
   --- controller ping statistics ---
   4 packets transmitted, 4 received, 0% packet loss, time 3000ms
   rtt min/avg/max/mdev = 0.202/0.217/0.263/0.030 ms