Configure Network Modes

This section provides detailed configuration instructions for each of the four Eucalyptus networking modes. Eucalyptus requires network connectivity between its clients (end-users) and the cloud components (CC, CLC, and Walrus). In Managed and Managed (No VLAN) modes, traffic to instances pass through the CC. So, in these two modes clients must be able to connect to the CC. In System and Static modes, clients need to connect directly to the NC. The CC does not act as a router in these two modes.

The /etc/eucalyptus/eucalyptus.conf file contains all network-related options in in the “Networking Configuration” section. These options use the prefix VNET_. The most commonly used VNET options are described in the following table. The set of networking settings that apply to a cloud varies based on its networking mode. Each setting in this section lists the modes in which it applies. Unless otherwise noted, all of these settings apply only to CCs.

The /etc/eucalyptus/eucalyptus.conf file contains all network-related options in in the Networking Configuration section. These options use the prefix VNET_. The most commonly used VNET options are described in the following table.

Option	Description	Modes
`VNET_MODE`	The networking mode in which to run. The same mode must be specified on all CCs and NCs in the entire cloud. Valid values: `STATIC`, `SYSTEM`, `MANAGED`, `MANAGED-NOVLAN`, Default: `SYSTEM`	All
`VNET_PRIVINTERFACE`	The name of the network interface that is on the same network as the NCs. In Managed and Managed (No VLAN) modes this must be a bridge for instances in different clusters but in the same security group to be able to reach one another with their private addresses. Default: `eth0`	Static Managed Managed (No VLAN)
`VNET_PUBINTERFACE`	On a CC, this is the name of the network interface that is connected to the “public” network. On an NC, this is the name of the network interface that is connected to the same network as the CC. Depending on the hypervisor's configuration this may be a bridge or a physical interface that is attached to the bridge. Default: `eth0`	Managed
`VNET_BRIDGE`	On an NC, this is the name of the bridge interface to which instances' network interfaces should attach. A physical interface that can reach the CC must be attached to this bridge. Common settings include `xenbr0` for older Xen versions, `eth0` for newer Xen versions, and `br0` for KVM.	Static System Managed (No VLAN)
`VNET_MACMAP`	A map of MAC addresses to IP addresses that Eucalyptus should allocate to instances when running in Static mode. Separate MAC addresses and IP addresses with = characters. Separate pairs with spaces. Example: `VNET_MACMAP="00:01:02:03:04:05=192.168.1.1 A1:A2:A3:A4:A5:A6=192.168.1.2"`	Static
`VNET_PUBLICIPS`	A space-separated list of individual and/or hyphenated ranges of public IP addresses to assign to instances. If this is undefined then instances will receive only private IP addresses. For example: VNET_PUBLICIPS="173.205.188.140-173.205.188.254"	Managed Managed (No-VLAN)
`VNET_SUBNET, VNET_NETMASK`	The address and network mask of the network the cloud should use for instances' private IP addresses.	Static Managed Managed (No VLAN)
`VNET_ADDRSPERNET`	Eucalyptus assigns a distinct subnet of private IP addresses to each security group. This setting dictates how many addresses each of these subnets should contain. Specify a power of 2 between 16 and 2048. This is directly related, though not equal, to the number of instances that may reside in each security group, as Eucalyptus reserves eleven addresses per security group.	Managed , Managed (No VLAN)
`VNET_DNS`	The address of the DNS server to supply to instances in DHCP responses.	Static Managed Managed (No VLAN)
`VNET_BROADCAST, VNET_ROUTER`	The network broadcast and default gateway to supply to instances in DHCP responses.	Static
`VNET_LOCALIP`	By default the CC automatically determines which IP address to use when setting up tunnels to other CCs. Set this to the IP address that other CCs can use to reach this CC if tunneling does not work.	Managed Managed (No-VLAN)
`VNET_DHCPDAEMON`	The ISC DHCP executable to use. This is set to a distro-dependent value by packaging. The internal default is `/usr/sbin/dhcpd3`.	Static Managed Managed (No VLAN)
`VNET_DHCPUSER`	The user the DHCP daemon runs as on your distribution. For CentOS 6 and RHEL 6, this is typically `root`. Default: `dhcpd`	Static Managed Managed (No VLAN)