LAG Formation Rules

  • A port can be a member of only a single LAG, which can be a static, dynamic, or keep-alive LAG.
  • RUCKUS ICX devices cannot form a LAG between two stacks using a RUCKUS optical breakout cable because the cable is not supported on a stack.
  • In a linear stack, all ports of the same LAG must be connected to the same unit. Otherwise, you may lose connectivity when a stack port is disconnected from the Active stack unit.
  • All ports configured in a LAG must be of the same configured speed, (for example, all auto or 1g or 10g, and so on).
  • All ports configured in a LAG must be of the same operational speed.
  • LAG formation rules are checked when a static or dynamic LAG is operational.
  • All ports configured in a LAG must be configured in the same VLAN.
  • All ports configured in a LAG must be configured with the same port attributes. The following lists contain Layer 2, Layer 3, and ACL requirements:
  • Layer 2 requirements:
    The LAG is rejected for the following reasons:
    • The LAG ports do not have the same untagged VLAN component.
    • The LAG ports do not share the same VLAN membership or do not share the same uplink VLAN membership.
    • The LAG ports are configured as member ports of another LAG.
  • Layer 3 requirements:

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

  • ACL requirements:

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

  • Properties of the member ports that are being added to the LAG must be identical with respect to the following parameters:
    • Port tag type (untagged or tagged port)
    • Configured port speed and duplex
    • Operational port speed and duplex
    • LAG is formed with different speed capability ports, but the speed change is supported only to the least common speed port.
    • TOS-based configuration: On deletion of the LAG, each port inherits the same TOS-based QoS configuration.

    To change port parameters, you must change them on the LAG virtual interface. 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 LAG is supported on 1-Gbps, 2.5-Gbps, 5-Gbps, 10-Gbps, 40-Gbps, and 100-Gbps ports.
  • A LAG is formed with ports that have different speed capabilities. A speed change is supported to the least common speed possible among the physical ports.
  • 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).
  • All the ports must be connected to the same physical or logical device at the other end.
  • The sFlow configuration can be enabled on an individual port within a LAG. sFlow cannot be configured on LAG virtual interface. sFlow must be configured in LAG mode for each of the member ports separately.
  • LAG virtual interface or any member ports of the LAG cannot be configured as sFlow source.
  • RUCKUS 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 delete the LAG and maintain the same speed on all ports in the LAG.
    Note: If both ports are 2.5-Gbps ports, and one of the ports is not part of a LAG, the device does not allow a speed change on that port. For example, in the 2.5-Gbps port pair of 25 and 26, if 25 is part of a LAG, the device does not change the speed of 26 without deleting the LAG that 25 is a part.
  • Error-disabled interface cannot be added to LAG. To add the interface to LAG, recover the interface from error-disabled state.