Reference Guide

● Configure the same VLT domain ID on peer devices. If a VLT domain ID mismatch occurs on VLT peers, the VLTi does not
activate.
● In a VLT domain, VLT peers support connections to network devices that connect to only one peer.
VLT interconnect
A VLTi is the link that synchronizes states between VLT peers. OS10 automatically adds VLTi ports to VLANs spanned across
VLT peers. VLTi ports are not supported as members of VLANs configured on only one peer.
● The system automatically provisions the required VLANs.
●
VLAN ID 4094 is reserved as an internal control VLAN for the VLT domain, and it is not user configurable.
● VLT peer switches operate as separate nodes with independent control and data planes for devices attached to non-VLT
ports.
● The VLTi synchronizes L2 and L3 control-plane information across the two nodes. The VLTi is used for data traffic only
when there is a link failure that requires using VLTi for data packets to reach their final destination.
● Traffic with an unknown destination MAC address, multicast, or broadcast traffic can cause flooding across the VLTi.
● MAC, ARP, IPv6 neighbors that are learned over VLANs across VLT peer nodes are synchronized across the nodes.
● In a VLT domain, LLDP, flow control, port monitoring, and jumbo frame features are supported on a VLTi.
Configure VLT
Verify that both VLT peer devices are running the same software version. For VRRP operation, configure VRRP groups and L3
routing on each VLT peer. To configure VLT and create a VLT domain where two devices are physically connected and provide a
single port-channel connection to access devices, configure settings on each VLT peer device.
1. To prevent loops in VLT domain, enable the STP globally (spanning-tree mode {rstp | rapid-pvst} command).
RSTP and RPVST+ modes are supported on VLT ports.
2. Create a VLT domain by configuring the same domain ID on each peer (vlt-domain command).
3. (Optional) To override the default VLT primary election mechanism based on the system MAC addresses of the VLT nodes,
configure a VLT node priority for each of the VLT nodes using the primary-priority command. Enter a lower priority
value for the desired primary VLT peer and a higher priority value for the desired secondary VLT peer.
4. Configure the VLT interconnect interfaces on each peer (discovery-interface command). After you configure both
sides of the VLTi, the primary and secondary roles in the VLT domain are automatically assigned if primary priority is not
configured.
5. (Optional) Manually reconfigure the default VLT MAC address. Configure the VLT MAC address in both the VLT peers.
6. (Optional) Configure a time interval to delay bringing up VLT ports after reload or peer-link restoration between the VLT
peer switches.
7. Configure the VLT backup link used for heartbeat timers (backup destination {ip-address | ipv6 ipv6–
address } [vrf management] [interval interval-time] command).
8. Configure VLT port-channels between VLT peers and an attached device (vlt-port-channel command). Assign the
same VLT port-channel ID from 1 to 1024 to interfaces on different peers that you bundle together so that peer interfaces
appear as a single VLT LAG to downstream devices.
9. Connect peer devices in a VLT domain to an attached access device or server.
Virtual Link Trunking
679