Configuring Aggregated Ethernet LACP

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Configuring Aggregated Ethernet LACP
For aggregated Ethernet interfaces, you can configure the Link Aggregation Control Protocol (LACP). LACP is one method of bundling several physical interfaces to form one logical interface. You can configure both VLAN-tagged and untagged aggregated Ethernet with or without LACP enabled.

LACP exchanges are made between actors and partners. An actor is the local interface in an LACP exchange. A partner is the remote interface in an LACP exchange.

LACP is defined in IEEE 802.3ad, Aggregation of Multiple Link Segments.

LACP was designed to achieve the following:

Automatic addition and deletion of individual links to the aggregate bundle without user intervention

Link monitoring to check whether both ends of the bundle are connected to the correct group

The JUNOS implementation of LACP provides link monitoring but not automatic addition and deletion of links.

The LACP mode can be active or passive. If the actor and partner are both in passive mode, they do not exchange LACP packets, which results in the aggregated Ethernet links not coming up. If either the actor or partner is active, they do exchange LACP packets. By default, LACP is in passive mode on aggregated Ethernet interfaces. To initiate transmission of LACP packets and response to LACP packets, you must enable LACP active mode.

To enable LACP active mode, include the lacp statement at the [edit interfaces interface-name aggregated-ether-options] hierarchy level, and specify the active option:
[edit interfaces interface-name aggregated-ether-options]
lacp active;
To restore the default behavior, include the lacp statement at the [edit interfaces interface-name aggregated-ether-options] hierarchy level, and specify the passive option:
[edit interfaces interface-name aggregated-ether-options]
lacp passive;
Configuring the LACP Interval

By default, the actor and partner send LACP packets every second. You can configure the interval at which the interfaces send LACP packets by including the periodic statement at the [edit interfaces interface-name aggregated-ether-options lacp] hierarchy level:
[edit interfaces interface-name aggregated-ether-options lacp]
periodic interval;
The interval can be fast (every second) or slow (every 30 seconds). You can configure different periodic rates on active and passive interfaces. When you configure the active and passive interfaces at different rates, the transmitter honors the receiver's rate.

NOTE: Source address filtering does not work when LACP is enabled. For more information about source address filtering, see Enabling Ethernet MAC Address Filtering.
Percentage policers are not supported on aggregated Ethernet interfaces with the CCC protocol family configured. For more information about percentage policers, see the JUNOS Policy Framework Configuration Guide.

Generally, LACP is supported on all untagged aggregated Ethernet interfaces. For more information, see Configuring Untagged Aggregated Ethernet Interfaces.

For M-series routers with enhanced Flexible PIC Concentrators (FPCs) and T-series routing platforms, LACP over VLAN-tagged aggregated Ethernet interfaces is supported. For 8-port, 12-port, and 48-port Fast Ethernet PICs, LACP over VLAN-tagged interfaces is not supported.

Tracing LACP Operations

To trace the operations of the LACP process, include the traceoptions statement at the [edit protocols lacp] hierarchy level:
[edit protocols lacp traceoptions]
    file filename <files number> <size size> <(world-readable | no-world-readable)>;

    flag flag <disable>;

}
You can specify the following flags in the protocols lacp traceoptions statement:

all—All LACP tracing operations

configuration—Configuration code

packet—Packets sent and received

process—LACP process events

protocol—LACP protocol state machine

routing-socket—Routing socket events

startup—Process startup events

For general information about tracing, see the tracing and logging information in the JUNOS System Basics Configuration Guide.

Example: Configuring Aggregated Ethernet LACP

LACP with VLAN-Tagged Aggregated Ethernet

Configure aggregated Ethernet LACP over a VLAN-tagged interface:
[edit interfaces]
fe-5/0/1 {
    fastether-options {
        802.3ad ae0;
    }
}
ae0 {
    aggregated-ether-options {
        lacp {
            active;
        }
    }
    vlan-tagging;
    unit 0 {
        vlan-id 100;
        family inet {
            address 10.1.1.2/24 {
                vrrp-group 0 {
                    virtual-address 10.1.1.4;
                    priority 200;
                }
            }
        }
    }
}
LACP with Untagged Aggregated Ethernet

Configure aggregated Ethernet LACP over an untagged interface:
[edit interfaces]
fe-5/0/1 {
    fastether-options {
        802.3ad ae0;
    }
}
ae0 {
    aggregated-ether-options {
        lacp {
            active;
        }
    }
    unit 0 {
        family inet {
            address 10.1.1.2/24 {
                vrrp-group 0 {
                    virtual-address 10.1.1.4;
                    priority 200;
                }
            }
        }
    }
}

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