Supported Platforms
Configuring Multichassis Link Aggregation
On MX Series routers, multichassis link aggregation (MC-LAG) enables a device to form a logical LAG interface with two or more other devices. MC-LAG provides additional benefits over traditional LAG in terms of node level redundancy, multi-homing support, and loop-free Layer 2 network without running Spanning Tree Protocol (STP). MC-LAG can be configured for VPLS routing instance, CCC application, and Layer 2 circuit encapsulation types.
The MC-LAG devices use Inter-Chassis Communication Protocol (ICCP) to exchange the control information between two MC-LAG network devices.
On one end of MC-LAG is a MC-LAG client device that has one or more physical links in a link aggregation group (LAG). This client device does not need to be aware of MC-LAG. On the other side of MC-LAG are two MC-LAG network devices. Each of these network devices has one or more physical links connected to a single client device. The network devices coordinate with each other to ensure that data traffic is forwarded properly.
MC-LAG includes the following functionality:
- Active standby mode is supported using Link Aggregation Control Protocol (LACP)
- MC-LAG operates only between two chassis.
- Layer 2 circuit functions are supported with ether-ccc encapsulation.
- VPLS functions are supported with ether-vpls and vlan-vpls.
 | Note: Ethernet connectivity fault management (CFM) specified in IEEE 802.1ag standard for Operation, Administration, and Management (OAM) is not supported on MC-LAG interfaces. |
To enable MC-LAG, include the mc-ae statement at the [edit interfaces aeX aggregated-ether-options] hierarchy level along with either the ethernet-bridge, encapsulation ethernet-ccc, encapsulation ethernet-vpls, or flexible-ethernet-services statement at the [edit interfaces aeX] hierarchy level. You also need to configure the lacp statement and the admin-key and system-id statements at the [edit interfaces aeX aggregated-ether-options] hierarchy level:
| Note: When you configure the prefer-status-control-active statement, you must also configure the status-control active statement. If you configure the status-control standby statement with the prefer-status-control-active statement, the system issues a warning. |
To delete a MC-LAG interface from the configuration, issue the delete interfaces aeX aggregated-ether-options mc-ae command at the [edit] hierarchy level in configuration mode:
Published: 2013-02-13
Supported Platforms
Related Documentation
- MX Series
- Active-Active Bridging and VRRP over IRB Functionality on MX Series Routers Overview
- Configuring Active-Active Bridging and VRRP over IRB in Multichassis Link Aggregation on MX Series Routers
- show interfaces mc-ae
- Additional Information
- Junos® OS Ethernet Interfaces
