LAG formation rules

  • A port can be a member of only a single LAG, which can be a static, dynamic, or keep-alive LAG.
  • Flexible LAG membership: Brocade ICX 7750, Brocade ICX 7450, and Brocade ICX 7250 devices support a maximum of 256 LAGs and each LAG supports a maximum of 16 member ports. However, Ruckus ICX 7150 device supports a maximum of 128 LAGs and each LAG supports a maximum of 8 member ports. The maximum number of LAG ports is checked when adding ports to a LAG. Ports in a LAG can be on different line card modules in a chassis or on different units in a stack.
    NOTE
    The Brocade ICX 7750, Brocade ICX 7450 and Brocade ICX 7250 devices can scale only up to a maximum of 2048 LAG ports. The maximum number of LAG ports supported on Ruckus ICX 7150 is 1024 and is also limited to the number of ports on the device.
  • Brocade FastIron devices cannot form a LAG between two stacks using a Brocade optical breakout cable because the cable is not supported on a stack.
  • All ports configured in a LAG must be of equal bandwidth, for example, all 10 GbE ports.
  • All ports configured in a LAG must be configured with the same port attributes.
  • LAG formation rules are checked when a static or dynamic LAG is deployed.
  • A LAG must have its primary port selected before it can be deployed.
  • All ports configured in a LAG must be configured in the same VLAN.
  • Layer 2 requirements:
    The LAG is rejected if the LAG ports:
    • Do not have the same untagged VLAN component
    • Do not share the same VLAN membership or do not share the same uplink VLAN membership
    • Do not share the same protocol-VLAN configuration
    • Are configured as mainly primary and secondary interfaces
  • Layer 3 requirements:

    The LAG is rejected if any of the secondary LAG port has any Layer 3 configurations, such as IPv4 or IPv6 address, OSPF, RIP, RIPng, IS-IS, and so on.

  • Layer 4 (ACL) requirements:

    All LAG ports must have the same ACL configurations; otherwise, the LAG is rejected.

  • All LAG member properties must match the primary port of the LAG with respect to the following parameters:
    • Port tag type (untagged or tagged port)
    • Port dual-mode
    • Default port speed and duplex
    • Configured port speed and duplex
    • TOS-based configuration: During deployment, the configuration on the primary port is replicated to all ports. On undeployment, each port inherits the same TOS-based QoS configuration.

    To change port parameters, you must change them on the primary port. The software automatically applies the changes to the other ports in the LAG.

  • The device on the other end of the LAG link must support the same number of ports in the link.
  • A combination of copper and fiber ports, even if they are of the same speed, cannot be members of the same LAG.
  • A LAG is supported on 1 GbE,10 GbE, or 40 GbE ports.
  • 1 GbE and 10 GbE ports cannot be combined in the same LAG.
  • Port assignment on a module need not be consecutive. The port range can contain gaps. For example, you can configure ports 1, 3, and 4 (excluding 2).
  • Although the FastIron devices have port ranges, they do not apply to LAGs.
  • You can select any port to be the primary port of the LAG.
  • All the ports must be connected to the same physical or logical device at the other end.
  • The sFlow configuration enabled on the primary port of a LAG is applicable to all the LAG ports. Disabling the sFlow on the primary port of a LAG removes the configuration from all the LAG ports.
  • Brocade FastIron ICX 7450 devices do not support change in speed of a 2.5G paired port, if at least one of the port is part of a LAG. To resolve this issue, you need to un-deploy the LAG and maintain the same speed on all ports in the LAG.
    NOTE
    If both the ports are 2.5G, and one of the ports is not part of a LAG, then the device does not allow speed change on this port as well. For example: 25 and 26 is a 2.5G port pair. If 25 is part of a LAG, then the device does not change the speed to 26 without un-deploying the LAG where 25 is part of.