# Configuring 802.3ad Link Aggregation

To configure link aggregation on Ethernet interfaces, you must configure the Ethernet interface, create the LAG bundle, and add the Ethernet interface as a member link in the LAG bundle. Optionally, you can then configure IP, a VLAN subinterface, a PPPoE subinterface, or MPLS for the LAG bundle.

For more information about specifying LAG interfaces and subinterfaces on E Series routers, see Interface Types and Specifiers in JunosE Command Reference Guide.

Tasks to configure 802.3ad link aggregation interfaces are:

1. Configuring an Ethernet Physical Interface
2. Configuring a LAG Bundle
3. Configuring IP for a LAG Bundle
4. Configuring IPv6 for a LAG Bundle
5. Configuring a VLAN Subinterface for a LAG Bundle
6. Configuring a PPPoE Subinterface for a LAG Bundle
7. Configuring MPLS for a LAG Bundle

## Configuring an Ethernet Physical Interface

To configure a member link, perform the following steps:

1. Specify a Fast Ethernet or Gigabit Ethernet interface for which you want to create a member link.
   host1(config)#interface gigabitEthernet 2/0
2. Configure LACP in passive or active mode.
   host1(config-if)#lacp active
3. Specify the speed and the duplex mode for the Ethernet interface.
   host1(config-if)#speed 100 host1(config-if)#duplex full
4. Specify the MTU.
   host1(config-if)#mtu 9000
5. To configure additional member links, repeat steps 1 through 4.

   | Note: All of the member links that you configure must be on the same line module and have the same physical layer characteristics, such as speed, duplex mode, and MTU.

## Configuring a LAG Bundle

To configure a LAG bundle and add member links, perform the following steps:

1. Create the LAG bundle.
   host1(config)#interface lag bundleBoston
2. Add a member link to the LAG bundle.
   host1(config-if)#member–interface gigabitEthernet 2/0
3. (Optional) Configure the minimum number of member links required in the LAG bundle for the LAG interface to be considered up.
   host1(config-if)#minimum-links 2

## Configuring IP for a LAG Bundle

To configure IP for a LAG bundle, perform the following steps:

1. Specify the LAG bundle.
   host1(config)#interface lag bundleBoston
2. Assign an IP address and mask.
   host1(config-if)#ip address 192.5.127.8 255.255.255.0

## Configuring IPv6 for a LAG Bundle

To configure an IPv6 address for a LAG bundle, perform the following steps:

1. Specify the LAG bundle.
   host1(config)#interface lag bundleBoston
2. Assign an IPv6 prefix address to the LAG bundle.
   host1(config-if)#ipv6 address 1::1/64

## Configuring a VLAN Subinterface for a LAG Bundle

To configure a VLAN subinterface for the LAG bundle, perform the following steps:

1. Specify VLAN as the encapsulation method.
   host1(config-if)#encapsulation vlan
2. Specify the VLAN subinterface for the LAG bundle by adding a unique subinterface number to the LAG interface identification command.
   host1(config)#interface lag bundleBoston.1
3. Assign a VLAN ID for the subinterface.
   host1(config-if)#vlan id 203
4. Assign an IP address and mask.
   host1(config-if)#ip address 192.168.1.1 255.255.0.0
5. Assign an IPv6 prefix address.
   host1(config-if)#ipv6 address 1::1/64

## Configuring a PPPoE Subinterface for a LAG Bundle

To configure a PPPoE subinterface for the LAG bundle, perform the following steps:

1. Specify PPPoE as the encapsulation method.
   host1(config-if)#encapsulation pppoe
2. Specify the PPPoE subinterface for the LAG bundle in either of the following ways:
   - Use the interface lag command to add a unique subinterface number to the LAG bundle name.
     host1(config)#interface lag bundleBoston.2
   - Use the pppoe subinterface lag command to add a unique subinterface number to the LAG bundle name.
     host1(config)#pppoe subinterface lag bundleBoston.2
3. Specify PPP as the encapsulation method on the PPPoE subinterface.
   host1(config-if)#encapsulation ppp
4. Assign an IP address and mask.
   host1(config-if)#ip address 192.168.1.2 255.255.0.0
5. Assign an IPv6 prefix address.
   host1(config-if)#ipv6 address 1::1/64

You can also configure a PPPoE subinterface over a VLAN subinterface over a LAG bundle. For an example of this configuration, see Example: Configuring 802.3ad Link Aggregation.

## Configuring MPLS for a LAG Bundle

To configure MPLS for a LAG bundle, perform the following steps:

1. Specify the LAG bundle.
   host1(config)#interface lag bundleBoston
2. Create an MPLS interface.
   host1(config-if)#mpls

#### Related Documentation

- Understanding 802.3ad Ethernet Link Aggregation
- Monitoring a Specified Ethernet Member Link in an IEEE 802.3ad LAG Bundle
- Monitoring Ethernet Member Links in all IEEE 802.3ad LAG Bundles
- encapsulation
- interface fastEthernet
- interface gigabitEthernet
- interface lag
- lacp
- lacp port-priority
- member-interface-type
- minimum-links
- mpls
- mtu
- pppoe subinterface
- virtual-router
- vlan id