Dell S4048T, Configuration Manual

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The recommended MTU for IPv6 is 1280. Greater MTU settings increase processing efficiency because each
packet carries more data while protocol overheads (for example, headers) or underlying per-packet delays
remain fixed.
Figure 59. Path MTU Discovery Process
IPv6 Neighbor Discovery
The IPv6 neighbor discovery protocol (NDP) is a top-level protocol for neighbor discovery on an IPv6
network.
In place of address resolution protocol (ARP), NDP uses “Neighbor Solicitation” and “Neighbor Advertisement”
ICMPv6 messages for determining relationships between neighboring nodes. Using these messages, an IPv6
device learns the link-layer addresses for neighbors known to reside on attached links, quickly purging
cached values that become invalid.
NOTE: If a neighboring node does not have an IPv6 address assigned, it must be manually pinged to allow
the IPv6 device to determine the relationship of the neighboring node.
NOTE: To avoid problems with network discovery, Dell Networking recommends configuring the static
route last or assigning an IPv6 address to the interface and assigning an address to the peer (the
forwarding router’s address) less than 10 seconds apart.
With ARP, each node broadcasts ARP requests on the entire link. This approach causes unnecessary
processing by uninterested nodes. With NDP, each node sends a request only to the intended destination via
IPv6 Routing 528