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Chapter 13. Configuring network teaming

This section describes the basics of network teaming, the differences between bonding and teaming, and how to configure a network team on Red Hat Enterprise Linux.

Important

Network teaming is deprecated in Red Hat Enterprise Linux 9. If you plan to upgrade your server to a future version of RHEL, consider using the kernel bonding driver as an alternative. For details, see Configuring network bonding.

You can create network teams on different types of devices, such as:

Physical and virtual Ethernet devices
Network bonds
Network bridges
VLAN devices

13.1. Understanding network teaming

Network teaming is a feature that combines or aggregates network interfaces to provide a logical interface with higher throughput or redundancy.

Network teaming uses a kernel driver to implement fast handling of packet flows, as well as user-space libraries and services for other tasks. This way, network teaming is an easily extensible and scalable solution for load-balancing and redundancy requirements.

Important

Certain network teaming features, such as the fail-over mechanism, do not support direct cable connections without a network switch. For further details, see Is bonding supported with direct connection using crossover cables?

13.2. Understanding the default behavior of controller and port interfaces

Consider the following default behavior of, when managing or troubleshooting team or bond port interfaces using the NetworkManager service:

Starting the controller interface does not automatically start the port interfaces.
Starting a port interface always starts the controller interface.
Stopping the controller interface also stops the port interface.
A controller without ports can start static IP connections.
A controller without ports waits for ports when starting DHCP connections.
A controller with a DHCP connection waiting for ports completes when you add a port with a carrier.
A controller with a DHCP connection waiting for ports continues waiting when you add a port without carrier.

13.3. Comparison of network teaming and bonding features

Learn about the features supported in network teams and network bonds:

Feature	Network bond	Network team
Broadcast Tx policy	Yes	Yes
Round-robin Tx policy	Yes	Yes
Active-backup Tx policy	Yes	Yes
LACP (802.3ad) support	Yes (active only)	Yes
Hash-based Tx policy	Yes	Yes
User can set hash function	No	Yes
Tx load-balancing support (TLB)	Yes	Yes
LACP hash port select	Yes	Yes
Load-balancing for LACP support	No	Yes
Ethtool link monitoring	Yes	Yes
ARP link monitoring	Yes	Yes
NS/NA (IPv6) link monitoring	No	Yes
Ports up/down delays	Yes	Yes
Port priorities and stickiness (“primary” option enhancement)	No	Yes
Separate per-port link monitoring setup	No	Yes
Multiple link monitoring setup	Limited	Yes
Lockless Tx/Rx path	No (rwlock)	Yes (RCU)
VLAN support	Yes	Yes
User-space runtime control	Limited	Yes
Logic in user-space	No	Yes
Extensibility	Hard	Easy
Modular design	No	Yes
Performance overhead	Low	Very low
D-Bus interface	No	Yes
Multiple device stacking	Yes	Yes
Zero config using LLDP	No	(in planning)
NetworkManager support	Yes	Yes

13.4. Understanding the teamd service, runners, and link-watchers

The team service, teamd, controls one instance of the team driver. This instance of the driver adds instances of a hardware device driver to form a team of network interfaces. The team driver presents a network interface, for example team0, to the kernel.

The teamd service implements the common logic to all methods of teaming. Those functions are unique to the different load sharing and backup methods, such as round-robin, and implemented by separate units of code referred to as runners. Administrators specify runners in JavaScript Object Notation (JSON) format, and the JSON code is compiled into an instance of teamd when the instance is created. Alternatively, when using NetworkManager, you can set the runner in the team.runner parameter, and NetworkManager auto-creates the corresponding JSON code.

The following runners are available:

broadcast: Transmits data over all ports.
roundrobin: Transmits data over all ports in turn.
activebackup: Transmits data over one port while the others are kept as a backup.
loadbalance: Transmits data over all ports with active Tx load balancing and Berkeley Packet Filter (BPF)-based Tx port selectors.
random: Transmits data on a randomly selected port.
lacp: Implements the 802.3ad Link Aggregation Control Protocol (LACP).

The teamd services uses a link watcher to monitor the state of subordinate devices. The following link-watchers are available:

ethtool: The libteam library uses the ethtool utility to watch for link state changes. This is the default link-watcher.
arp_ping: The libteam library uses the arp_ping utility to monitor the presence of a far-end hardware address using Address Resolution Protocol (ARP).
nsna_ping: On IPv6 connections, the libteam library uses the Neighbor Advertisement and Neighbor Solicitation features from the IPv6 Neighbor Discovery protocol to monitor the presence of a neighbor’s interface.

Each runner can use any link watcher, with the exception of lacp. This runner can only use the ethtool link watcher.

13.5. Installing the teamd service

To configure a network team in NetworkManager, you require the teamd service and the team plug-in for NetworkManager. Both are installed on Red Hat Enterprise Linux by default. This section describes how you install the required packages in case that you remove them.

Prerequisites

An active Red Hat subscription is assigned to the host.

Procedure

Install the teamd and NetworkManager-team packages:
```
# yum install teamd NetworkManager-team
```

13.6. Configuring a network team using nmcli commands

This section describes how to configure a network team using nmcli utility.

Important

Prerequisites

Two or more physical or virtual network devices are installed on the server.
To use Ethernet devices as ports of the team, the physical or virtual Ethernet devices must be installed on the server and connected to a switch.
To use bond, bridge, or VLAN devices as ports of the team, you can either create these devices while you create the team or you can create them in advance as described in:

Procedure

Create a team interface:
```
# nmcli connection add type team con-name team0 ifname team0 team.runner activebackup
```
This command creates a network team named team0 that uses the activebackup runner.
Optionally, set a link watcher. For example, to set the ethtool link watcher in the team0 connection profile:
```
# nmcli connection modify team0 team.link-watchers "name=ethtool"
```
Link watchers support different parameters. To set parameters for a link watcher, specify them space-separated in the name property. Note that the name property must be surrounded by quotes. For example, to use the ethtool link watcher and set its delay-up parameter to 2500 milliseconds (2.5 seconds):
```
# nmcli connection modify team0 team.link-watchers "name=ethtool delay-up=2500"
```
To set multiple link watchers and each of them with specific parameters, the link watchers must be separated by a comma. The following example sets the ethtool link watcher with the delay-up parameter and the arp_ping link watcher with the source-host and target-host parameter:
```
# nmcli connection modify team0 team.link-watchers "name=ethtool delay-up=2, name=arp_ping source-host=192.0.2.1 target-host=192.0.2.2"
```
Display the network interfaces, and note the names of the interfaces you want to add to the team:
```
# nmcli device status
DEVICE  TYPE      STATE         CONNECTION
enp7s0  ethernet  disconnected  --
enp8s0  ethernet  disconnected  --
bond0   bond      connected  bond0
bond1   bond      connected  bond1
...
```
In this example:
- enp7s0 and enp8s0 are not configured. To use these devices as ports, add connection profiles in the next step. Note that you can only use Ethernet interfaces in a team that are not assigned to any connection.
- bond0 and bond1 have existing connection profiles. To use these devices as ports, modify their profiles in the next step.
Assign the port interfaces to the team:
1. If the interfaces you want to assign to the team are not configured, create new connection profiles for them:
```
# nmcli connection add type ethernet slave-type team con-name team0-port1 ifname enp7s0 master team0
# nmcli connection add type ethernet slave-type team con-name team0-port2 ifname enp8s0 master team0
```
  . These commands create profiles for enp7s0 and enp8s0, and add them to the team0 connection.
2. To assign an existing connection profile to the team, set the master parameter of these connections to team0:
```
# nmcli connection modify bond0 master team0
# nmcli connection modify bond1 master team0
```
  These commands assign the existing connection profiles named bond0 and bond1 to the team0 connection.

Configure the IP settings of the team. Skip this step if you want to use this team as a ports of other devices.

Configure the IPv4 settings. For example, to set a static IPv4 address, network mask, default gateway, DNS server, and DNS search domain the team0 connection, enter:

# nmcli connection modify team0 ipv4.addresses '192.0.2.1/24'
# nmcli connection modify team0 ipv4.gateway '192.0.2.254'
# nmcli connection modify team0 ipv4.dns '192.0.2.253'
# nmcli connection modify team0 ipv4.dns-search 'example.com'
# nmcli connection modify team0 ipv4.method manual

Configure the IPv6 settings. For example, to set a static IPv6 address, network mask, default gateway, DNS server, and DNS search domain of the team0 connection, enter:

# nmcli connection modify team0 ipv6.addresses '2001:db8:1::1/64'
# nmcli connection modify team0 ipv6.gateway '2001:db8:1::fffe'
# nmcli connection modify team0 ipv6.dns '2001:db8:1::fffd'
# nmcli connection modify team0 ipv6.dns-search 'example.com'
# nmcli connection modify team0 ipv6.method manual

Activate the connection:
```
# nmcli connection up team0
```

Verification steps

Display the status of the team:

# teamdctl team0 state
setup:
  runner: activebackup
ports:
  enp7s0
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 0
  enp8s0
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 0
runner:
  active port: enp7s0

In this example, both ports are up.

Additional resources

Testing basic network settings
Configuring NetworkManager to avoid using a specific profile to provide a default gateway
Understanding the teamd service, runners, and link-watchers
nmcli-examples(7) man page
The team section in the nm-settings(5) man page
teamd.conf(5) man page

13.7. Configuring a network team using nm-connection-editor

This section describes how you configure a network team using the nm-connection-editor application.

Note that nm-connection-editor can add only new ports to a team. To use an existing connection profile as a port, create the team using the nmcli utility as described in Configuring a network team using nmcli commands.

Important

Prerequisites

Two or more physical or virtual network devices are installed on the server.
To use Ethernet devices as ports of the team, the physical or virtual Ethernet devices must be installed on the server.
To use team, bond, or VLAN devices as ports of the team, ensure that these devices are not already configured.

Procedure

Open a terminal, and enter nm-connection-editor:
```
$ nm-connection-editor
```
Click the + button to add a new connection.
Select the Team connection type, and click Create.
In the Team tab:
1. Optional: Set the name of the team interface in the Interface name field.
2. Click the Add button to add a new connection profile for a network interface and adding the profile as a port to the team.
  1. Select the connection type of the interface. For example, select Ethernet for a wired connection.
  2. Optional: Set a connection name for the port.
  3. If you create a connection profile for an Ethernet device, open the Ethernet tab, and select in the Device field the network interface you want to add as a port to the team. If you selected a different device type, configure it accordingly. Note that you can only use Ethernet interfaces in a team that are not assigned to any connection.
  4. Click Save.
3. Repeat the previous step for each interface you want to add to the team.
4. Click the Advanced button to set advanced options to the team connection.
  1. In the Runner tab, select the runner.
  2. In the Link Watcher tab, set the link watcher and its optional settings.
  3. Click OK.
Configure the IP settings of the team. Skip this step if you want to use this team as a port of other devices.
1. In the IPv4 Settings tab, configure the IPv4 settings. For example, set a static IPv4 address, network mask, default gateway, DNS server, and DNS search domain:
2. In the IPv6 Settings tab, configure the IPv6 settings. For example, set a static IPv6 address, network mask, default gateway, DNS server, and DNS search domain:
Save the team connection.
Close nm-connection-editor.

Verification steps

Display the status of the team:

# teamdctl team0 state
setup:
  runner: activebackup
ports:
  enp7s0
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 0
  enp8s0
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
        down count: 0
runner:
  active port: enp7s0

Additional resources

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Chapter 13. Configuring network teaming

13.1. Understanding network teaming

13.2. Understanding the default behavior of controller and port interfaces

13.3. Comparison of network teaming and bonding features

13.4. Understanding the teamd service, runners, and link-watchers

13.5. Installing the teamd service

13.6. Configuring a network team using nmcli commands

13.7. Configuring a network team using nm-connection-editor