the peer-link port-channel id-number peer-down-vlan vlan interface number command
and the switchport command. After you specify the VLTi link and VLT LAGs, you can associate the
same port channel or LAG bundle that is a part of a VLT to a PVLAN by using the interface interface
and switchport mode private-vlan commands.
When a VLTi port in trunk mode is a member of symmetric VLT PVLANs, the PVLAN packets are
forwarded only if the PVLAN settings of both the VLT nodes are identical. You can configure the VLTi in
trunk mode to be a member of non-VLT PVLANs if the VLTi is configured on both the peers. MAC address
synchronization is performed for VLT PVLANs across peers in a VLT domain.
Keep the following points in mind when you configure VLT nodes in a PVLAN:
• Configure the VLTi link to be in trunk mode. Do not configure the VLTi link to be in access or
promiscuous mode.
• 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 the 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 primary or secondary VLANs 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 parity is
not validated if you associate an ICL to a PVLAN. Similarly, if you dissociate an ICL from a PVLAN,
although the PVLAN parity exists, ICL is removed from that PVLAN.
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 a member of that
VLAN if the VLTi link is configured as a PVLAN or 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 parity on both the 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 the 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 the VLAN based on the validation of the VLAN parity.
For VLT VLANs, the association between primary VLAN and secondary VLANs 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. For example, 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.
Virtual Link Trunking (VLT) 997