# Example: Configuring 802.3ad Link Aggregation

The examples in this section illustrate how to configure 802.3ad Link Aggregation.

- Requirements
- Overview of Configuring 802.3ad Link Aggregation
- Example: Configuring an IP Interface for a LAG Bundle
- Example: Configuring a PPPoE Subinterface for a LAG Bundle
- Example: Configuring a PPPoE Subinterface over a VLAN for a LAG Bundle
- Example: Configuring MPLS for a LAG Bundle
- Example: Configuring MPLS over a VLAN for a LAG Bundle

### Requirements

This example uses the following hardware and software components:

- JunosE Release 7.1.0 or higher-numbered releases
- E Series router (ERX7xx models, ERX14xx models, the ERX310 router, the E120 router, or the E320 router)
- ASIC-based line modules that support Fast Ethernet or Gigabit Ethernet

### Overview of Configuring 802.3ad Link Aggregation

IEEE 802.3ad link aggregation enables you to group Ethernet interfaces at the physical layer to form a single link layer interface, also known as a link aggregation group (LAG) or bundle. For more information, see IEEE Standard 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.

### Example: Configuring an IP Interface for a LAG Bundle

#### Step-by-Step Procedure

To configure an IP Interface for a LAG bundle:

1. Configure a Fast Ethernet interface in slot 0.
   host1(config)#interface fastEthernet 0/0 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp active

   | Note: In a LAG group, member interfaces can be added only from a single slot. For ERX platforms, member interfaces can be added from both of the I/O adapters from a slot.

2. Similarly, configure another Fast Ethernet interface in slot 0.
   host1(config)#interface fastEthernet 0/5 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp active

   | Note: The interfaces are enabled for active LACP. The speed and duplex characteristics are the same for both the interfaces.

3. Create a virtual router.
   host1(config-if)#virtual-router boston

   | Note: LAG is not specific to any virtual router. A LAG interface is visible and can be used in any virtual router.

4. Create a LAG bundle named bundleBoston and add the Ethernet physical interfaces to it.
   host1:boston(config)#interface lag boston host1:boston(config-if)#member-interface fastEthernet 0/0 host1:boston(config-if)#member-interface fastEthernet 0/5
5. Assign an IP address and mask.
   host1:boston(config-if)#ip address 1.1.1.1 255.255.255.0
6. Assign an IPv6 address.
   host1:boston(config-if)#ipv6 address 1::1/64

### Example: Configuring a PPPoE Subinterface for a LAG Bundle

#### Step-by-Step Procedure

To configure a PPPoE Subinterface for a LAG bundle:

1. Configure a Fast Ethernet interface in slot 4.
   host1(config)#interface fastEthernet 4/0 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp passive
2. Similarly, configure another Fast Ethernet interface in slot 4.
   host1(config)#interface fastEthernet 4/3 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp passive

   | Note: The interfaces are enabled for passive LACP. The speed and duplex characteristics are the same for both the interfaces.

3. Add the Ethernet physical interfaces to a LAG bundle named chicago.
   host1(config)#interface lag chicago host1(config-if)#member-interface fastEthernet 4/0 host1(config-if)#member-interface fastEthernet 4/3
4. Specify PPPoE as the encapsulation method.
   host1(config-if)#encapsulation pppoe
5. Add a unique subinterface number to the LAG bundle name. In the LAG interface identification command (interface lag chicago.1), the number 1 represents the subinterface number for the PPPoE subinterface.
   host1(config)#interface lag chicago.1

   | Note: As an alternative to using the command interface lag chicago.1 to configure the PPPoE subinterface in this example, you can also use the command pppoe subinterface lag chicago.1 to achieve the same result.

6. Specify PPP as the encapsulation method on the PPPoE subinterface.
   host1(config-if)#encapsulation ppp
7. Assign an IP address and mask.
   host1(config-if)#ip address 10.10.1.1 255.255.0.0
8. Assign an IPv6 prefix address.
   host1(config-if)#ipv6 address 1::1/64

### Example: Configuring a PPPoE Subinterface over a VLAN for a LAG Bundle

#### Step-by-Step Procedure

To configure a PPPoE subinterface over a VLAN for a LAG bundle:

1. Configure a Fast Ethernet interface in slot 3.
   host1(config)#interface fastEthernet 3/0 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp active
2. Similarly, configure another Fast Ethernet interface in slot 3.
   host1(config)#interface fastEthernet 3/1 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp active

   | Note: The interfaces are enabled for active LACP. The speed and duplex characteristics are the same for both the interfaces.

3. Add the Ethernet physical interfaces to a LAG bundle named sunnyvale.
   host1(config)#interface lag sunnyvale host1(config-if)#member-interface fastEthernet 3/0 host1(config-if)#member-interface fastEthernet 3/1
4. Configure a VLAN subinterface for the LAG bundle named sunnyvale. In the LAG interface identification command (interface lag sunnyvale.1), the number 1 represents the subinterface number for the VLAN subinterface.
   host1(config-if)#encapsulation vlan host1(config)#interface lag sunnyvale.1 host1(config-if)#vlan id 100
5. Configure a PPPoE subinterface over the VLAN subinterface for the LAG bundle named sunnyvale. In the LAG interface identification command (interface lag sunnyvale.1.2), the number 2 represents the subinterface number for the PPPoE subinterface.
   host1(config-if)#encapsulation pppoe host1(config)#interface lag sunnyvale.1.2

   | Note: As an alternative to using the command interface lag sunnyvale.1.2 to configure the PPPoE subinterface in this example, you can also use the command pppoe subinterface lag sunnyvale.1.2 to achieve the same result.

6. Specify PPP as the encapsulation method on the PPPoE subinterface.
   host1(config-if)#encapsulation ppp
7. Assign an IP address and mask.
   host1(config-if)#ip address 10.10.2.2 255.255.0.0
8. Assign an IPv6 prefix address.
   host1(config-if)#ipv6 address 1::1/64

### Example: Configuring MPLS for a LAG Bundle

#### Step-by-Step Procedure

To configure MPLS for a LAG bundle:

1. Configure a Fast Ethernet interface in slot 5.
   host1(config)#interface fastEthernet 5/0 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp active
2. Similarly, configure another Fast Ethernet interface in slot 5.
   host1(config)#interface fastEthernet 5/1 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp active

   | Note: The interfaces are enabled for active LACP. The speed and duplex characteristics are the same for both the interfaces.

3. Create a virtual router.
   host1(config-if)#virtual-router kanata
4. Create a LAG bundle named kanata and add the Ethernet physical interfaces to it.
   host1:kanata(config)#interface lag kanata host1:kanata(config-if)#member-interface fastEthernet 0/0 host1:kanata(config-if)#member-interface fastEthernet 0/5
5. Assign an IP address and mask.
   host1:kanata(config-if)#ip address 1.1.1.1 255.255.255.0
6. Configure an MPLS interface.
   host1(config-if)#mpls

### Example: Configuring MPLS over a VLAN for a LAG Bundle

#### Step-by-Step Procedure

To configure MPLS over a VLAN for a LAG bundle:

1. Configure a Fast Ethernet interface in slot 5.
   host1(config)#interface fastEthernet 5/0 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp active
2. Similarly, configure another Fast Ethernet interface in slot 5.
   host1(config)#interface fastEthernet 5/1 host1(config-if)#speed 100 host1(config-if)#duplex full host1(config-if)#lacp active

   | Note: The interfaces are enabled for active LACP. The speed and duplex characteristics are the same for both the interfaces.

3. Create a virtual router.
   host1(config)#virtual-router kanata
4. Create a LAG bundle named kanata and add the Ethernet physical interfaces to it.
   host1:kanata(config)#interface lag kanata host1:kanata(config-if)#member-interface fastEthernet 5/0 host1:kanata(config-if)#member-interface fastEthernet 5/1
5. Configure a VLAN subinterface for the LAG bundle named kanata. In the LAG interface identification command (interface lag kanata.1), the number 1 represents the subinterface number for the VLAN subinterface.
   host1:kanata(config-if)#encapsulation vlan host1:kanata(config)#interface lag sunnyvale.1 host1:kanata(config-if)#vlan id 100
6. Configure an MPLS interface.
   host1(config-if)#mpls

#### Related Documentation

- Understanding 802.3ad Ethernet Link Aggregation
- Configuring 802.3ad Link Aggregation
- encapsulation
- interface fastEthernet
- interface gigabitEthernet
- interface lag
- lacp
- lacp port-priority
- member-interface-type
- minimum-links
- mpls
- mtu
- pppoe subinterface
- virtual-router
- vlan id