Dell S4148U-ON OS10 Enterprise Edition User Guide Release 10.4.0E R2 - Page 315

only. Neighbor Discovery (ND) messages advertise so the neighbor can use the information to auto-configure its address. Received ND messages are not used to create an IPv6 address. Inconsistencies in router advertisement values between routers are logged. The values checked for consistency include: • Current hop limit • M and O flags • Reachable time • Retransmission timer • MTU options • Preferred and valid lifetime values for the same prefix The router redirect functionality in the Neighbor Discovery protocol (NDP) is similar to IPv4 router redirect messages. NDP uses ICMPv6 redirect messages (Type 137) to inform nodes that a better router exists on the link. Neighbor discovery The IPv6 Neighbor Discovery protocol (NDP) determines if neighboring IPv6 devices are reachable and receives the IPv6 addresses of IPv6 devices on local links. Using the link-layer and global prefixes of neighbor addresses, OS10 performs stateless autoconfiguration of IPv6 addresses on interfaces. ICMPv6 Router Advertisement messages advertise the IPv6 addresses of IPv6-enabled interfaces and allow a router to learn of any address changes in IPv6 neighbors. By default, router advertisements are disabled on an interface. Prerequisites To enable RA messages, the switch must be in Router mode with IPv6 forwarding enabled and stateless autoconfiguration disabled (no ipv6 address autoconfig command). Enable router advertisement messages 1 Enable IPv6 neighbor discovery and sending ICMPv6 RA messages in Interface mode. ipv6 nd send-ra 2 (Optional) Configure IPv6 neighbor discovery options in Interface mode. • ipv6 nd hop-limit hops - (Optional) Sets the hop limit advertised in RA messages and included in IPv6 data packets sent by the router (0 to 255; default 64). 0 indicates that no hop limit is specified by the router. • ipv6 nd managed-config-flag - (Optional) Sent in RA messages to tell hosts to use stateful address autoconfiguration, such as DHCPv6, to obtain IPv6 addresses. • ipv6 nd max-ra-interval seconds - (Optional) Sets the maximum time interval for sending RA messages (4 to 1800 seconds; default 600). • ipv6 nd mtu number - (Optional) Sets the maximum transmission unit (MTU) used in RA messages on the link (1280 to 65535 bytes; default 1500). By default, no MTU setting is included in RA messages. • ipv6 nd other-config-flag - (Optional) Tells hosts to use stateful autoconfiguration to obtain nonaddress-related information. • ipv6 nd ra-lifetime seconds - (Optional) Sets the lifetime of a default router in RA messages (0 to 9000 milliseconds; default 3 times the max-ra-interval setting). 0 indicates that this router is not used as a default router. • ipv6 nd reachable-time milliseconds - (Optional) Sets the advertised time for which the router sees that a neighbor is up after it receives neighbor reachability confirmation (0 to 3600000 milliseconds; default 0). 0 indicates that no reachable time is sent in RA messages. • ipv6 nd retrans-timer seconds - (Optional) Sets the time between retransmitting neighbor solicitation messages (100 to 4292967295 milliseconds). By default, no retransmit timer is configured. Layer 3 315