Dell S4048–ON Configuration Manual page 946

Figure 145. Sample Configuration of IPv6 Peer Routing in a VLT Domain
Neighbor Solicitation from VLT Hosts
Consider a case in which NS for VLT node1 IP reaches VLT node1 on VLT interface and NS for VLT node1 IP reaches VLT node2 due
to LAG level hashing in TOR. When VLT node1 receives NS from VLT VLAN interface, it unicasts NA packet on the VLT interface.
When NS reaches VLT node2 it is flooded on all interfaces including ICL. When VLT node 1 receives NS on ICL then it floods NA
packet on the VLAN. If NS is unicast and if reaches wrong VLT peer it is lifted to CPU using ACL entry. Then wrong peer adds tunnel
header and forwards the packet over ICL.
Neighbor Advertisement from VLT Hosts
Consider an example in which NA for VLT node1 reaches VLT node1 on VLT interface and NA for VLT node1 reaches VLT node2 due
to LAG level hashing in TOR. When VLT node1 receives NA on VLT interface, it learns the Host MAC address on VLT interface. This
learned neighbor entry is synchronized to VLT node2 as it is learned on VLT interface of Node2. If VLT node2 receives a NA packet
on VLT interface which is destined to VLT node1, node 2 will lift the NA packet to CPU using an ACL entry then it adds a tunnel
header to the received NA and forwards the packet to VLT node1 over ICL. When VLT node1 receives NA over ICL with tunnel
header it learns the Host MAC address on VLT port channel interface. This learned neighbor entry is synchronized to VLT node2 as it
is learned on VLT interface of Node2.
If NA is intended for VLT peer and DIP is LLA of peer, it is lifted to CPU and tunneled to the peer. VLT nodes will drop NA packet, If
NA is received over ICL without tunneling header.
Neighbor Solicitation from Non-VLT Hosts
Consider a sample scenario in which NS for VLT node1 IP reaches VLT node1 on non-VLT interface and NS for VLT node1 IP reaches
VLT node2 on non-VLT interface. When VLT node1 receives NS from non-VLT interface, it unicasts NA packet on the received
interface. When NS reaches VLT node2 it is VLAN flooded on all interfaces including ICL. When VLT node 1 receives NS on ICL then
it floods NA packet on the VLAN. If NS is unicast and if reaches wrong VLT peer it is lifted to CPU using ACL entry. Then wrong peer
adds tunnel header and forwards the packet over ICL
Neighbor Advertisement from Non-VLT Hosts
946
Virtual Link Trunking (VLT)