Addendum

• You can configure a VLT LAG or port channel to be in trunk, access, or promiscuous port modes
when you include the VLT LAG in a PVLAN. The VLT LAG settings must be the same on both the peers.
If you configure a VLT LAG as a trunk port, you can associate that LAG to be a member of a normal
VLAN or a PVLAN. If you configure a VLT LAG to be a promiscuous port, you can configure that LAG
to be a member of PVLAN only. If you configure a VLT LAG to be in access port mode, you can add
that LAG to be a member of secondary VLAN only.
• ARP entries are synchronized even when a mismatch occurs in the PVLAN mode of a VLT LAG.
Any VLAN that contains at least one VLT port as a member is treated as a VLT VLAN. You can configure a
VLT VLAN to be a primary, secondary, or a normal VLAN. However, the VLT VLAN configuration must be
symmetrical across peers. If the VLT LAG is tagged to any one of the secondary VLANs of a PVLAN or
primary VLAN of a PVLAN, then both the primary and secondary VLANs are considered as VLT VLANs.
If you add an ICL or VLTi link as a member of a primary VLAN, the ICL becomes a part of the primary
VLAN and its associated secondary VLANs, similar to the behavior for normal trunk ports. VLAN
symmetricity is not validated if you associate an ICL to a PVLAN. Similarly, if you dissociate an ICL from a
PVLAN, although the PVLAN symmetricity exists, ICL is removed from that PVLAN in such a case.
Association of VLTi as a Member of a PVLAN
If a VLAN is configured as a non-VLT VLAN on both the peers, the VLTi link is made as a member of that
VLAN if the VLTi link is configured as a PVLAN/normal VLAN on both the peers. If a PVLAN is configured
as a VLT VLAN on one peer and a non-VLT VLAN on another peer, the VLTi is added as a member of that
VLAN by verifying the PVLAN symmetricity on both peers. In such a case, if a PVLAN is present as a VLT
PVLAN on at least one of the peers, then symmetric configuration of PVLAN is validated to cause the VLTi
to be a member of that VLAN. Whenever a change in the VLAN mode on one of the peers occurs, the
information is synchronized with the other peer and VLTi is either added or removed from VLAN based
on the validation of the LAN symmetricity.
For VLT VLANs, the association between primary VLAN and secondary VLAN is examined on both the
peers. Only if the association is identical on both the peers, VLTi is configured as a member of those
VLANs. This behavior is because of security functionalities in a PVLAN. If a VLAN is a primary VLT VLAN on
one peer and not a primary VLT VLAN on the other peer, VLTi is not made a part of that VLAN. If a VLAN is
secondary VLT VLAN on one peer and not a secondary VLT VLAN on the other peer, VLTi is not a part of
that VLAN. If a VLAN is a normal VLT VLAN on one peer and a VLT PVLAN on the other peer, VLTi is not
processed as a member of that VLAN.
MAC Synchronization for VLT Nodes in a PVLAN
For the MAC addresses that are learned on non-VLT ports, MAC address synchronization is performed
with the other peer if the VLTi (ICL) link is part of the same VLAN as the non-VLT port. For MAC addresses
that are learned on VLT ports, the VLT LAG mode of operation and the primary to secondary association
of the VLT nodes is determined on both the VLT peers. MAC synchnronization is performed for the VLT
LAGs only if the VLT LAG and primary-secondary VLT peer mapping are symmetrical.
The PVLAN mode of VLT LAGs on one peer is validated against the PVLAN mode of VLT LAGs on the
other peer. MAC addresses are learned on that VLT LAG are synchronzied between the peers only if the
PVLAN mode on both the peers is identical. If the MAC address is learned on a VLT LAG and the VLAN is a
primary VLT VLAN on one peer and not a primary VLT VLAN on the other peer, MAC synchronization
does not occur. Similarly, if the MAC address is learned on a VLT LAG and the VLAN is a secondary VLT
VLAN on one peer and not a secondary VLT VLAN on the other peer, MAC synchronization does not
occur. Additionally, if the MAc address is learned on a VLT LAG and the VLAN is a normal VLT VLAN on
one peer and not a normal VLT VLAN on the other peer, MAC synchronization does not occur.
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Virtual Link Trunking (VLT)