Addendum

You can configure VLT nodes that function as RP as Multicast Source Discovery Protocol (MSDP) peers in
different domains. However, you cannot configure the VLT peers as MSDP peers in the same VLT domain.
In such a case, RP functionality is not supported by the VLT peer.
If the same source or RP is can be accessed over both a VLT and a non-VLT VLAN, you must configure
better metrics for the VLT VLANs. Otherwise, it is possible that one VLT node chooses a non-VLT VLAN (if
the path through the VLT Vlan was not available when the route was learnt) and another VLT node selects
a VLT Vlan. Such a scenario can cause duplication of packets. ECMP is not supported when you configure
VLT nodes as RPs.
Backup RP is not supported if VLT peer that functions as the RP is statically configured. With static RP
configuration, if the RP reboots, it can handle new clients only after it comes back online. Until the RP
returns to the active state, the VLT peer forwards the packets for the already logged-in clients. To enable
the VLT peer node to retain the synchronized multicast routes or synchronized multicast outgoing
interface (OIF) maps after a peer node failure , the timeout value that you configured by using the
multicast peer-routing timeout value command is used. You can configure the time for a VLT
node to retain synced multicast routes or synced multicast outgoing interface (OIF) after a VLT peer node
failure by using the multicast peer-routing-timeout command in VLT DOMAIN mode to be an
optimal value. Using the bootstrap router (BSR) mechanism, both the VLT nodes in a VLT domain can be
configured as the candidate RP for the same group range. When an RP fails, the VLT peer automatically
takes over the role of the RP. This phenomenon enables resiliency to be achieved by the PIM BSR
protocol.
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Virtual Link Trunking (VLT)