7. Network Configuration

The Network section of the administrative GUI contains the following components for viewing and configuring the TrueNAS® system’s network settings:

  • CARPs:_ used when configuring high availablility.
  • Global Configuration: used to to set non-interface specific network settings.
  • Interfaces: used to configure a specified interface’s network settings.
  • IPMI: provides side-band management should the appliance become unavailable through the graphical administrative interface.
  • Link Aggregations: used to configure link aggregation and link failover.
  • Network Summary: provides an overview of the current network settings.
  • Static Routes: used to add static routes.
  • VLANs: used to configure IEEE 802.1q tagging.

Each of these is described in more detail in this section.

7.1. CARPs

Network -> CARPs is used to configure the CARP information that is used when configuring high availability in System -> Failovers.

Failover using CARP is only available on certain appliances and requires an advanced configuration between multiple TrueNAS® appliances that is created with the assistance of an iXsystems support engineer. Failover can only be used with iSCSI or NFS. Contact your iXsystems representative if you wish to schedule a time to configure failover. Do not attempt to configure CARP on your own as it will fail and may render existing shares or volumes inaccessible.

This section provides an overview of CARP terminology and the CARP screen that appears in the graphical administrative utility.

The following terminology is used by CARP:

Redundancy group: a group of hosts on a network segment which are assigned the same virtual IP address. Within the group, one host is designated the “master” and the rest are considered “backups”. The master responds to any traffic directed at the virtual IP address.

Advertisements: the master sends regular network packets known as advertisements so the backups know that it is still available. If the backups don’t receive an advertisement from the master for a set period of time, the backup host with the lowest configured advertisements skew value will take over as master.

Advertisements Skew: measured in 1/256 of a second. The value is added to the advertisement interval in order to make one host advertise a bit slower than the other.

Virtual host ID: allows group members to identify which redundancy group the advertisement belongs to.

Password: in order to prevent a malicious user from spoofing CARP advertisements, each group can be configured with a password.

Figure 7.1a shows the configuration screen that appears when you click Network -> CARPs -> Add CARP. Table 7.1a describes the available configuration options.

Figure 7.1a: Adding a CARP


Table 7.1a: CARP Configuration Options

Setting Value Description
Interface Number number number, beginning with 0, used to identify the CARP interface
Virtual Host ID integer allowed values range from 1 to 255; use the same value for all members of the redundancy group
Password string use the same value for all members of the redundancy group
Advertisements Skew integer change this value on the backup that should be promoted to master should the original master become unavailable

7.2. Global Configuration

Network –> Global Configuration, shown in Figure 7.2a, allows you to set non-interface specific network settings.

Table 7.2a summarizes the settings that can be configured using the “Global Configuration” tab. The hostname and domain will be pre-filled for you, as seen in Figure 5.1a, but can be changed to meet the local network’s requirements.

If you will be using `Active Directory`_, set the IP address of the DNS server used in the realm.

If your network does not have a DNS server or NFS, SSH, or FTP users are receiving “reverse DNS” or timeout errors, add an entry for the IP address of the TrueNAS® system in the “Host name database” field.


if you add a gateway to the Internet, make sure that the TrueNAS® system is protected by a properly configured firewall.

Figure 7.2a: Global Configuration Screen


Table 7.2a: Global Configuration Settings

Setting Value Description
Hostname string system host name
Domain string system domain name
IPv4 Default Gateway IP address typically not set (see NOTE below)
IPv6 Default Gateway IP address typically not set (see NOTE below)
Nameserver 1 IP address primary DNS server (typically in Windows domain)
Nameserver 2 IP address secondary DNS server
Nameserver 3 IP address tertiary DNS server
Enable netwait feature checkbox if enabled, network services will not be started at boot time until the interface is able to ping the addresses listed in “Netwait IP list”
Netwait IP list string if “Enable netwait feature” is checked, list of IP addresses to ping; otherwise, ping the default gateway
Host name database string used to add one entry per line which will be appended to /etc/hosts; use the format IP_address space hostname where multiple hostnames can be used if separated by a space


in many cases, a TrueNAS® configuration will deliberately exclude default gateway information as a way to make it more difficult for a remote attacker to communicate with the server. While this is a reasonable precaution, such a configuration does not restrict inbound traffic from sources within the local network. However, omitting a default gateway will prevent the TrueNAS® system from communicating with DNS servers, time servers, and mail servers that are located outside of the local network. In this case, it is recommended that Static Routes be added in order to reach external DNS, NTP, and mail servers which are configured with static IP addresses.

7.3. Interfaces

Network –> Interfaces is used to view which interfaces have been manually configured, to add a manually configured interface, and to edit an interface’s manual configuration.


typically the interface used to access the TrueNAS® administrative GUI is configured by DHCP. This interface will not appear in this screen, even though it is already dynamically configured and in use.

Figure 7.3a shows the screen that opens when you click Interfaces –> Add Interface. Table 7.3a summarizes the configuration options when you “Add” an interface or Edit an already configured interface.

Figure 7.3a: Adding or Editing an Interface


Table 7.3a: Interface Configuration Settings

Setting Value Description
NIC drop-down menu select the FreeBSD device name; will be a read-only field when editing an interface
Interface Name string description of interface
DHCP checkbox requires static IPv4 or IPv6 configuration if unchecked; note that only one interface can be configured for DHCP
IPv4 Address IP address set if DHCP unchecked
IPv4 Netmask drop-down menu set if DHCP unchecked
Auto configure IPv6 checkbox only one interface can be configured for this option; requires manual configuration if unchecked and wish to use IPv6
IPv6 Address IPv6 address must be unique on network
IPv6 Prefix Length drop-down menu match the prefix used on network
Options string additional parameters from ifconfig(8) , one per line; for example: mtu 9000 will increase the MTU for interfaces that support jumbo frames

This screen also allows you to configure an alias for the interface. If you wish to set multiple aliases, click the “Add extra alias” link for each alias you wish to configure. To delete an alias, highlight the interface in the tree to access its “Edit” screen. Be sure to check the “Delete” checkbox associated with the alias. If you instead click the “Delete” button at the bottom of this screen, you will delete the whole interface, not just the alias.

When configuring multiple interfaces, they can not be members of the same subnet. Check the subnet mask if you receive an error when setting the IP addresses on multiple interfaces.

When configuring an interface for both IPv4 and IPv6, this screen will not let you set both addresses as primary. In other words, you will get an error if you fill in both the “IPv4 address” and “IPv6 address” fields. Instead, set one of these address fields and create an alias for the other address.

7.4. IPMI

TrueNAS® provides a graphical screen for configuring the built-in IPMI interface.

IPMI provides side-band management should the system become unavailable through the graphical administrative interface. This allows for a few vital functions, such as checking the log, accessing the BIOS setup, and powering on the system without requiring physical access to the system. IPMI can also be used to allow another person remote access to the system in order to assist with a configuration or troubleshooting issue. Before configuring IPMI, ensure that the management interface is physically connected to the network. Depending upon the hardware, the IPMI device may share the primary Ethernet interface or it may be a dedicated IPMI interface.

IPMI should be configured from Network –> IPMI. Figure 7.4a shows the configuration screen and Table 7.4a summarizes the options when configuring IPMI.

Figure 7.4a: IPMI Configuration


Table 7.4a: IPMI Options

Setting Value Description
Password string input the password used to connect to the IPMI interface from a web browser
DHCP checkbox if left unchecked, the following three fields must be set
IPv4 Address string IP address used to connect to the IPMI web GUI
IPv4 Netmask drop-down menu subnet mask associated with the IP address
IPv4 Default Gateway string default gateway associated with the IP address

Once configured, you can access the IPMI interface using a web browser and the IP address you specified in the configuration. The management interface will prompt for a username and the password that you configured. Refer to the documentation for the IPMI device to determine the default administrative username.

The default username is ADMIN (in all caps). Once you have logged into the management interface, you can change the administrative username as well as create additional users. The appearance of the utility and the functions that are available within the IPMI management utility will vary depending upon the hardware.

7.6. Network Summary

Network –> Network Summary allows you to quickly view the addressing information of every configured interface. For each interface name, the configured IP address(es), DNS server(s), and default gateway will be displayed.

7.7. Static Routes

By default, no static routes are defined on the TrueNAS® system. Should you need a static route to reach portions of your network, add the route using Network –> Static Routes –> Add Static Route, shown in Figure 7.7a.

Figure 7.7a: Adding a Static Route


The available options are summarized in Table 7.7a.

Table 7.7a: Static Route Options

Setting Value Description
Destination network integer use the format A.B.C.D/E where E is the CIDR mask
Gateway integer input the IP address of the gateway
Description string optional

If you add any static routes, they will show in “View Static Routes”. Click a route’s entry to access its “Edit” and “Delete” buttons.

7.8. VLANs

TrueNAS® uses FreeBSD’s vlan(4) interface to demultiplex frames with IEEE 802.1q tags. This allows nodes on different VLANs to communicate through a layer 3 switch or router. A vlan interface must be assigned a parent interface and a numeric VLAN tag. A single parent can be assigned to multiple vlan interfaces provided they have different tags. If you click Network –> VLANs –> Add VLAN, you will see the screen shown in Figure 7.8a.


VLAN tagging is the only 802.1q feature that is implemented.

Figure 7.8a: Adding a VLAN


Table 7.8a summarizes the configurable fields.

Table 7.8a: Adding a VLAN

Setting Value Description
Virtual Interface string use the format vlanX where X is a number representing the vlan interface
Parent Interface drop-down menu usually an Ethernet card connected to a properly configured switch port; if using a newly created lagg device, it will not appear in the drop-down until the system is rebooted
VLAN Tag integer should match a numeric tag set up in the switched network
Description string optional

The parent interface of a vlan has to be up, but it can have an IP address or it can be unconfigured, depending upon the requirements of the VLAN configuration. This makes it difficult for the GUI to do the right thing without trampling the configuration. To remedy this, after adding the VLAN, go to Network –> Interfaces –> Add Interface. Select the parent interface from the NIC drop-down menu and in the “Options” field, type up. This will bring up the parent interface. If an IP address is required, it can be configured using the rest of the options in the “Add Interface” screen.