Configuring MCLAG Configuring Multi-chassis Link Aggregation
page 10-28 OmniSwitch AOS Release 7 Network Configuration Guide June 2013
Chassis Group ID
• Each peer switch also requires a chassis group ID number to identify the switch as belonging to that
specific multi-chassis group (a pair of multi-chassis peer switches).
• The group ID is appended to the MAC address generated for all MCLAG virtual IP (VIP) VLANs on a
chassis to prevent duplicate MAC addresses from occurring in an MCLAG network environment. This
is particularly important in a back-to-back MCLAG setup, but configuring the group ID is highly
recommended in all MCLAG configurations.
• Changing the group ID at runtime is allowed; t is not necessary to reboot the switch to activate the new
group ID value.
• The same group ID number is assigned to each peer switch in the multi-chassis group. Peer switches
belonging to other multi-chassis groups must use a different group ID number.
• If the peer switches within the same multi-chassis group do not have the same group ID number, the
operational state of the MCLAG will remain down due to an inconsistency.
• If two or more separate multi-chassis groups use the same group ID number, this inconsistency is not
detected or corrected by MCLAG functionality. It is up to the administrator to ensure that each domain
uses a unique group ID.
For information about configuring the chassis group ID, see “Configuring the Group ID” on page 10-30,
and “Example 2: MCLAG Group ID Configuration” on page 10-37.
Virtual Fabric Link (VFL)
• The operational state of the multi-chassis functionality depends on the VFL operational state.
• The Link Aggregation Control Protocol (LACP) is used to monitor the state of the VFL. Aggregate ID
128 is reserved for and assigned to VFL aggregated ports.
• Explicitly configuring the VFL and the physical port members is required. Configure the VFL only
during network maintenance time or when MCLAG is first configured. Changing VFL configuration at
runtime can cause undesirable disruption to traffic flows.
• It is recommended to configure the VFL at the same time as the chassis identifier. This ensures that the
switch reboots with the correct VFL configuration.
• For increased resiliency, member ports should be distributed across different switching ASICs and NI
modules.
• Only physical ports operating at 10-Gbps or 40-Gbps can be members of a VFL.
• For resiliency it is recommended to have more than one member port configured for the VFL, they are
bundled to form a single logical link. All the member ports must operate at the same speed.
• The VFL automatically becomes a member of all VLANs.
• The hello interval parameter must match between chassis peers. The hello protocol runs across the VFL
link between the peers.
For more information on Virtual Fabric Link, see “Creating the Virtual Fabric Link (VFL)” on page 10-30