Users Guide

This delay in bringing up the VLT ports also applies when the VLTi link recovers from a failure that caused the VLT ports on the secondary
VLT peer node to be disabled.
PIM-Sparse Mode Support on VLT
The designated router functionality of the PIM Sparse-Mode multicast protocol is supported on VLT peer switches for multicast sources
and receivers that are connected to VLT ports.
VLT peer switches can act as a last-hop router for IGMP receivers and as a rst-hop router for multicast sources.
Figure 154. PIM-Sparse Mode Support on VLT
On each VLAN where the VLT peer nodes act as the rst hop or last hop routers, one of the VLT peer nodes is elected as the PIM
designated router. If you congured IGMP snooping along with PIM on the VLT VLANs, you must congure VLTi as the static multicast
router port on both VLT peer switches. This ensures that for rst hop routers, the packets from the source are redirected to the designated
router (DR) if they are incorrectly hashed. In addition to being rst-hop or last -hop routers, the peer node can also act as an intermediate
router.
1090
Virtual Link Trunking (VLT)