Administrator Guide
IPv6 Neighbor Discovery
IPv6 neighbor discovery protocol (NDP) is supported on the MXL swtich platform.
NDP is a top-level protocol for neighbor discovery on an IPv6 network. In lieu 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 conguring 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 a multicast address with the unicast address used
as the last 24 bits. Other hosts on the link do not participate in the process, greatly increasing network bandwidth eciency.
Figure 56. NDP Router Redirect
IPv6 Neighbor Discovery of MTU Packets
With the Dell Networking OS version 8.3.1.0, you can set the MTU advertised through the RA packets to incoming routers, without
altering the actual MTU setting on the interface.
The ipv6 nd mtu command sets the value advertised to routers. It does not set the actual MTU rate. For example, if you set
ipv6 nd mtu to 1280, the interface still passes 1500-byte packets, if that is what is set with the mtu command.
Conguring the IPv6 Recursive DNS Server
You can congure up to four Recursive DNS Server (RDNSS) addresses to be distributed via IPv6 router advertisements to an IPv6
device, using the ipv6 nd dns-server ipv6-RDNSS-address {lifetime | infinite} command in INTERFACE
CONFIG mode.
IPv6 Addressing
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