Service Manual

When a VLT node receives traffic from north bound intended to the VLT host, it does neighbor entry
lookup and routes traffic to VLT interface. If VLT interface is not operationally up the VLT node routes the
traffic over ICL. If neighbor entry is not present the VLT node will resolve the destination. There may be
traffic loss during neighbor resolution period.
VLT host to Non-VLT host traffic flow
When VLT node receives traffic intended to non-VLT host, it routes the traffic over non-VLT interface. If
the traffic intended to non-VLT host reaches wrong VLT peer due to LAG hashing in TOR, the wrong VLT
node will resolve the destination over ICL and routes the traffic over ICL. When Correct VLT node
receives this routed traffic over ICL it will switch traffic to non-VLT interface.
Non-VLT host to VLT host traffic flow
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
1086
Virtual Link Trunking (VLT)