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When VLT node receives traffic from non-VLT host intended to VLT host, it routes the traffic to VLT interface. If VLT interface
is not operationally up VLT node will route the traffic over ICL.
Non-VLT host to North Bound traffic flow
When VLT node receives traffic from non-VLT host intended to north bound with DMAC as self MAC it routes traffic to next
hop. When VLT node receives traffic from non-VLT host intended to north bound with DMAC as peer MAC it will not forward
the packet to VLT peer instead it will route the traffic to north bound next hop.
North Bound to Non-VLT host traffic flow
When VLT node receives traffic from north bound intended to the non-VLT host, it does neighbor entry lookup and routes
traffic to VLT interface. If traffic reaches wrong VLT peer, it routes the traffic over ICL.
Non-VLT host to Non-VLT host traffic flow
When VLT node receives traffic from non-VLT host intended to the non-VLT host, it does neighbor entry lookup and routes
traffic over ICL interface. If traffic reaches wrong VLT peer, it routes the traffic over ICL.
Router Solicitation
When VLT node receives router Solicitation on VLT interface/non-VLT interface it consumes the packets and will send RA back
on the received interface.
VLT node will drop the RS message if it is received over ICL interface.
Router Advertisement
When VLT node receives router advertisement on VLT interface/non-VLT interface it consumes the packets.
VLT node will drop the RA message if it is received over ICL interface.
Upgrading from Releases That Do Not Support IPv6 Peer Routing
During an upgrade to Release 9.4(0.0) from earlier releases, VLT peers might contain different versions of FTOS. You must
upgrade both the VLT peers to Release 9.4(0.0) to leverage the benefits of IPv6 peer routing.
Station Movement
When a host moves from VLT interface to non-VLT interface or vice versa Neighbor entry is updated and synchronized to VLT
peer. When a host moves from non-VLT interface of VLT node1 to non-VLT interface of VLT node2 neighbor entry is updated
and synchronized to VLT peer.
Configure BFD in VLT Domain
Dell EMC Networking OS supports Bidirectional Forwarding Detection (BFD) to detect communication failures on an interface
that is a part of a VLT link aggregation group (LAG).
In VLT domain, BFD provides high availability path when there are communication failures in any one of the VLT LAG links.
The VLT nodes and top of rack (ToR) use the VLT LAG links to carry the BFD packets. When any one of the VLT LAG links
connected to the ToR is down, the BFD packets reach the VLT primary or secondary using the VLTi (ICL) link.
Sample BFD configuration in VLT domain
The following shows the sample configuration of BFD implementation in VLT environment:
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Virtual Link Trunking (VLT)