Users Guide

are connected to the ToR (Node B) generate Layer 3 control/data traffic from the South or lower-end of the
vertically-aligned network.
Figure 133. 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 the VLT interface and NS for VLT node1
IP reaches VLT node2 due to LAG level hashing in the ToR. When VLT node1 receives NS from VLT VLAN
interface, it unicasts the 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, it floods the NA packet on the VLAN. If NS is
unicast and if it reaches the wrong VLT peer, it is lifted to the CPU using ACL entry. Then wrong peer adds a
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 the 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 lifts 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 a VLT peer and DIP is LLA of the peer, it is lifted to the CPU and tunneled to the peer. VLT
nodes drop the NA packet if the NA is received over ICL without a tunneling header.
Virtual Link Trunking (VLT) 1084