IPv6 Neighbor Discovery

IPv6 neighbor discovery uses ICMP messages and solicited multicast addresses to find the link layer address of a neighbor on the same local network, verify the neighbor‘s reachability and track neighboring devices.

Upon receiving a neighbor solicitation message, the destination replies with NA (neighbor advertisement). The source address in the advertisement is the IPv6 address of the device sending the message. The destination address in the advertisement message is the IPv6 address of the device sending the neighbor solicitation. The data portion of the NA includes the link layer address of the node sending the neighbor advertisement.

Neighbor solicitation messages also verify the availability of a neighbor once its the link layer address is identified. When a node wants to verify the reachability of a neighbor, the destination address in a neighbor solicitation message is the unicast address of the neighbor.

A neighbor is interpreted as reachable when an acknowledgment is returned indicating packets have been received and processed. If packets are reaching the device, they‘re also reaching the next hop neighbor, providing a confirmation the next hop is reachable.

To view a controller or service platform‘s IPv6 neighbor statistics:

1. Select the Statistics menu from the Web UI.
2. Expand the System node from the navigation pane (on the left-hand side of the screen). The System node expands to display the RF Domains created within the managed network.
3. Expand the RF Domain node.
4. Select a Wireless Controller.
5. Expand the Network menu from the left-hand side of the UI.
6. Select IPv6 Neighbor Discovery.

   The Statistics > Controller > Network > IPv6 Neighbor Discovery screen is displayed in the right-hand pane.

   This screen displays the following:

   IPv6 Address Lists an IPv6 IP address for neighbor discovery. IPv6 hosts can configure themselves automatically when connected to an IPv6 network using the neighbor discovery protocol via CMPv6 router discovery messages. When first connected to a network, a host sends a link-local router solicitation multicast request for its configuration parameters; routers respond to such a request with a router advertisement packet that contains Internet Layer configuration parameters. IPv6 addresses are composed of eight groups of four hexadecimal digits separated by colons. MAC Address Lists the factory encoded hardware MAC address of the neighbor device using an IPv6 formatted IP address as its network identifier. Type Displays the device type for the neighbor solicitation. Neighbor solicitations request the link layer address of a target node while providing the sender‘s own link layer address to the target. Neighbor solicitations are multicast when the node needs to resolve an address and unicast when the node seeks to verify the reachability of a neighbor. Options include Host, Router and DHCP Server. VLAN Lists the virtual interface (from 1 - 4094) used for the required neighbor advertisements and solicitation messages used for neighbor discovery.

7. Select Refresh to update the screen‘s statistics counters to their latest values.