Users Guide

The router redirect functionality in the 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 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 prexes of neighbor addresses, OS10 performs stateless autoconguration of IPv6 addresses on interfaces.
ICMPv6 RA messages advertise the IPv6 addresses of IPv6-enabled interfaces and allow a router to learn of any address changes in IPv6
neighbors. By default, RAs are disabled on an interface.
Prerequisites
To enable RA messages, the switch must be in Router mode with IPv6 forwarding enabled and stateless autoconguration disabled using
the 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) Congure 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, from 0 to 255; default 64.
0 indicates that no hop limit is specied by the router.
• ipv6 nd managed-config-flag — (Optional) Sent in RA messages to tell hosts to use stateful address autoconguration,
such as DHCPv6, to obtain IPv6 addresses.
• ipv6 nd max-ra-interval seconds — (Optional) Sets the maximum time interval for sending RA messages, from 4 to
1800 seconds; default 600.
• ipv6 nd mtu number — (Optional) Sets the maximum transmission unit (MTU) used in RA messages on the link, from 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 autoconguration to obtain nonaddress-related
information.
• ipv6 nd ra-lifetime seconds — (Optional) Sets the lifetime of a default router in RA messages, from 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 the router sees that a neighbor is up
after it receives neighbor reachability conrmation, from 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,
from 100 to 4292967295 milliseconds. By default, no retransmit timer is congured.
3 Congure the IPv6 prexes that are advertised by IPv6 neighbor discovery in Interface mode.
ipv6 nd prefix {ipv6-prefix | default} [no-advertise] [no-autoconfig] [no-rtr-address]
[off-link] [lifetime {valid-lifetime
seconds | infinite}
{preferred-lifetime seconds | infinite}]
• ipv6-prefix — Enter an IPv6 prex in x:x::y/mask format to include the prex in RA mesages. Include prexes that are not
already in the subnets congured on the interface.
• default — Congure the prex parameters advertised in all subnets congured on the interface.
• no-advertise — (Optional) Do not advertise the specied prex. By default, all prexes in congured subnets are advertised.
• no-autoconfig — (Optional) Sets AdvAutonomous to Off for the specied prex in the radvd.conf le. This setting tells
hosts to not use this prex for address autoconguration. By default,
AdvAutonomous is On.
• no-rtr-address — (Optional) Sets AdvRouterAddr to Off for the prex in the radvd.conf le. The Off setting tells hosts
to not use the advertising router address for on-link determination. By default,
AdvRouterAddr is On.
• off-link — (Optional) Sets AdvOnLink to Off for the prex in the radvd.conf le. The Off setting tells hosts to not use this
prex for on-link determination. By default,
AdvOnLink is On.
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Layer 3