Service Manual

One of the VLT peer is congured as default gateway router on VLT hosts. If VLT node receives L3 trac intended for the other VLT
peer it routes the trac to next hop instead of forwarding the trac to the VLT peer. If neighbor entry is not present VLT node will
resolve the next hop. There may be trac loss during neighbor resolution period.
North-Bound to VLT host trac ow
When a VLT node receives trac from north bound intended to the VLT host, it does neighbor entry lookup and routes trac to VLT
interface. If VLT interface is not operationally up the VLT node routes the trac over ICL. If neighbor entry is not present the VLT
node will resolve the destination. There may be trac loss during neighbor resolution period.
VLT host to Non-VLT host trac ow
When VLT node receives trac intended to non-VLT host, it routes the trac over non-VLT interface. If the trac 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 trac over ICL. When Correct VLT node receives this routed trac over ICL it will switch trac to non-VLT interface.
Non-VLT host to VLT host trac ow
When VLT node receives trac from non-VLT host intended to VLT host, it routes the trac to VLT interface. If VLT interface is not
operationally up VLT node will route the trac over ICL.
Non-VLT host to North Bound trac ow
When VLT node receives trac from non-VLT host intended to north bound with DMAC as self MAC it routes trac to next hop.
When VLT node receives trac 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 trac to north bound next hop.
North Bound to Non-VLT host trac ow
When VLT node receives trac from north bound intended to the non VLT host, it does neighbor entry lookup and routes trac to
VLT interface. If trac reaches wrong VLT peer, it routes the trac over ICL.
Non-VLT host to Non-VLT host trac ow
When VLT node receives trac from non-VLT host intended to the non-VLT host, it does neighbor entry lookup and routes trac
over ICL interface. If trac reaches wrong VLT peer, it routes the trac 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 dierent versions of FTOS. You must upgrade
both the VLT peers to Release 9.4(0.0) to leverage the benets of IPv6 peer routing.
Station Movement
844
Virtual Link Trunking (VLT)