Ipv6 Neighbor Discovery; Additional References - Cisco ASR 9000 Series Configuration Manual

IPv6 Neighbor Discovery

IPv6 Neighbor Discovery
The IPv6 neighbor discovery process uses Internet Control Message Protocol (ICMP) messages and
solicited-node multicast addresses to determine the link-layer address of a neighbor on the same network
(local link), verify the reachability of a neighbor, and track neighboring routers.
The IPv6 static cache entry for neighbor discovery feature allows static entries to be made in the IPv6 neighbor
cache. Static routing requires an administrator to manually enter IPv6 addresses, subnet masks, gateways, and
corresponding Media Access Control (MAC) addresses for each interface of each device into a table. Static
routing enables more control but requires more work to maintain the table. The table must be updated each
time routes are added or changed.
The different message types in neighbor discovery are:
• IPv6 Neighbor Solicitation Message: A value of 135 in the Type field of the ICMP packet header
• IPv6 Router Advertisement Message: Router advertisement (RA) messages, which have a value of 134
• IPv6 Neighbor Redirect Message: A value of 137 in the type field of the ICMP packet header identifies
In BNG, IPv6 neighbor discovery supports both IPoE and PPPoE sessions. IPv6 neighbor discovery provides
Stateless Address Auto Configuration (SLAAC), which is used for assigning a prefix to the PPPoE subscriber.

Additional References

These sections provide references related to implementing PPP, PPPoE, L2TP, and DHCP.
RFCs
Standard/RFC - PPP
RFC-1332
RFC-1570
RFC-1661
RFC-1994
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identifies a neighbor solicitation message. Neighbor solicitation messages are sent on the local link when
a node wants to determine the link-layer address of another node on the same local link.
in the Type field of the ICMP packet header, are periodically sent out each configured interface of an
IPv6 device.
Ambiguous VLAN does not have association with any particular VLAN, and therefore, a unicast router
advertisement message has to be sent out for ambiguous VLAN interfaces. To enable IPv6 unicast router
advertisement, you must use the ipv6 nd ra-unicast command in the dynamic template configuration
mode.
an IPv6 neighbor redirect message. Devices send neighbor redirect messages to inform hosts of better
first-hop nodes on the path to a destination.
Establishing Subscriber Sessions
Title
The PPP Internet Protocol Control Protocol (IPCP)
PPP LCP Extensions
The Point-to-Point Protocol (PPP)
PPP Challenge Handshake Authentication Protocol
(CHAP)
OL-28375-03