Connectivity Guide

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.
• lifetime {valid-lifetime seconds | infinite} — (Optional) Sets AdvValidLifetime in seconds for the
prex in the radvd.conf le. The prex is valid for on-link determination only for the specied lifetime. The default is 86400
seconds (1 day). The
infinite setting allows the prex to be valid for on-link determination with no time limit.
• lifetime {preferred-lifetime seconds | infinite} — (Optional) Sets AdvPreferredLifetime in seconds
for the prex in the radvd.conf le. IPv6 addresses generated from the prex using stateless autoconguration remain preferred
for the congured lifetime. The default is 14400 seconds (4 hours). The
infinite setting allows addresses that are
autocongured using the prex to be preferred with no time limit.
By default, all prexes congured in IPv6 addresses on an interface are advertised. To modify the default values advertised for
interface subnet prexes, use the ipv6 nd prefix default command and specify new default settings.
On-link determination is the process used to forward IPv6 packets to a destination IPv6 address.
Layer 3
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