Red Hat Enterprise Linux Implementation

Configuring Network Teaming

Managing Network Teaming

Configuring Software Bridges

Links NICs together logically

Implemented with small kernel driver and teamd user-space daemon

Implements load-balancing and active-backup logic with runners

All network interaction occurs through team interface composed of multiple port interfaces

Note following when using NetworkManager to control teamed port interfaces:

To create and manage team and port interfaces, use nmcli

To create and activate network team interface:

To create connection for network team interface, use nmcli

nmcli con add type team con-name CNAME ifname INAME [config JSON]

JSON has following syntax:

'{"runner": {"name": "METHOD"}}'

[root@demo ~]# nmcli con add type team con-name team0 ifname team0 config '{"runner": {"name": "loadbalance"}}'

After creating network team interface, assign IPv4 and/or IPv6 attributes

To create port interface, use nmcli

nmcli con add type team-slave con-name CNAME ifname INAME master TEAM

To manage connections for team and port interfaces, use nmcli with following syntax:

nmcli dev dis INAME
nmcli con up CNAME

To display state of team interface when it is up, use teamdctl

[root@demo ~]# teamdctl team0 state
setup:
  runner: roundrobin
ports:
  eth1
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
  eth2
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up

Man pages: nmcli-examples(5), teamdctl(8), and teamd(8)

NetworkManager creates teaming configuration files in /etc/sysconfig/network-scripts

Creates file for each interface: team and each port

Team interface file defines IP settings for interface

DEVICETYPE defines this as network team interface

TEAM_CONFIG defines teamd configuration parameters

Example: Configure file for team port interface

# /etc/sysconfig/network-scripts/ifcfg-team0-eth1
DEVICE=eth1
DEVICETYPE=TeamPort
TEAM_MASTER=team0
NAME=team0-eth1
ONBOOT=yes

DEVICETYPE defines this as team port interface

TEAM_MASTER specifies team device associated with port

Initial network team configuration is set when creating team interface

Default runner is roundrobin

To assign different runner or adjust runner parameters, use nmcli con mod

Determine how link state of port interfaces are monitored

Default settings use functionality similar to ethtool to check link of each interface

"link_watch": {
    "name": "ethtool"
}

Can also check link state and remote connectivity with arp_ping

"link_watch":{
    "name": "arp_ping",
    "interval": 100,
    "missed_max": 30,
    "source_host": "192.168.23.2",
    "target_host": "192.168.23.1"
},

Use teamnl and teamdctl to troubleshoot network teams that are up

To display team ports of team0 interface:

[root@demo ~]# teamnl team0 ports
 4: eth2: up 0Mbit HD
 3: eth1: up 0Mbit HD

To display currently active port of team0:

[root@demo ~]# teamnl team0 getoption activeport
3

To set option for active port of team0:

[root@demo ~]# teamnl team0 setoption activeport 3

To display current state of team0 interface, use teamdctl

[root@demo ~]# teamdctl team0 state
setup:
  runner: activebackup
ports:
  eth2
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
  eth1
    link watches:
      link summary: up
      instance[link_watch_0]:
        name: ethtool
        link: up
runner:
  active port: eth1

To display current JSON configuration for team0, use teamdctl

[root@demo ~]# teamdctl team0 config dump
{
    "device": "team0",
    "mcast_rejoin": {
        "count": 1
    },
    "notify_peers": {
        "count": 1
    },
    "ports": {
        "eth1": {
            "link_watch": {
                "name": "ethtool"
            },
            "prio": -10,
            "sticky": true
        },
        "eth2": {
            "link_watch": {
                "name": "ethtool"
            },
            "prio": 100
        }
    },
    "runner": {
        "name": "activebackup"
    }
}

Man pages: teamd.conf(5) and teamnl(8)

Network bridge: Link-layer device that forwards traffic between networks based on MAC addresses

Software bridge can emulate hardware bridge

Commonly used in virtualization applications

To configure persistent software bridges, use nmcli

Create software bridge, then connect interfaces to it

Example: Create bridge called br0 and attach eth1 and eth2 interfaces to it

[root@demo ~]# nmcli con add type bridge con-name br0 ifname br0
[root@demo ~]# nmcli con add type bridge-slave con-name br0-port1 ifname eth1 master br0
[root@demo ~]# nmcli con add type bridge-slave con-name br0-port2 ifname eth2 master br0

NetworkManager can attach only Ethernet interfaces to bridge

Software bridges managed by interface configuration files in /etc/sysconfig/network-scripts

Each software bridge has ifcfg-* file

# /etc/sysconfig/network-scripts/ifcfg-br1
DEVICE=br1
NAME=br1
TYPE=Bridge
BOOTPROTO=none
IPADDR0=192.168.0.1
PREFIX0=24
STP=yes
BRIDGING_OPTS=priority=32768

TYPE=Bridge specifies software bridge

BRIDGING_OPTS defines additional bridge options

Example: Attach Ethernet interface to software bridge

# /etc/sysconfig/network-scripts/ifcfg-br1-port0
TYPE=Ethernet
NAME=br1-port0
DEVICE=eth1
ONBOOT=yes
BRIDGE=br1

BRIDGE=br1 ties interface to software bridge br1

To implement software bridge on existing teamed or bonded network interface managed by NetworkManager, disable NetworkManager

To display software bridges and list the interfaces attached to them, use brctl show

[root@demo ~]# brctl show
bridge name     bridge id               STP enabled     interfaces
br1             8000.52540001050b       yes             eth1

Man pages: nmcli-examples(5) and brctl(8)

Configuring Network Teaming

Managing Network Teaming

Configuring Software Bridges