Connectivity Guide
To enable RA messages, the switch must be in Router mode with IPv6 forwarding enabled and stateless autoconguration 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) Congure 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 specied by the router.
• ipv6 nd managed-config-flag — (Optional) Sent in RA messages to tell hosts to use stateful address autoconguration,
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 autoconguration 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 conrmation, 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 congured.
3 Congure the IPv6 prexes 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 prex in x:x::y/mask format to include the prex in RA mesages. Include prexes that are not
already in the subnets congured on the interface.
• default — Congure the prex parameters advertised in all subnets congured on the interface.
• no-advertise — (Optional) Do not advertise the specied prex. By default, all prexes in congured subnets are advertised.
• no-autoconfig — (Optional) Sets AdvAutonomous to Off for the specied prex in the radvd.conf le. This setting tells
hosts to not use this prex for address autoconguration. By default,
AdvAutonomous is On.
• no-rtr-address — (Optional) Sets AdvRouterAddr to Off for the prex 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 prex in the radvd.conf le. The Off setting tells hosts to not use this
prex for on-link determination. By default,
AdvOnLink is On.
• lifetime {valid-lifetime seconds | infinite} — (Optional) Sets AdvValidLifetime in seconds for the
prex in the radvd.conf le. The prex is valid for on-link determination only for the specied lifetime. The default is 86400
seconds (1 day). The
infinite setting allows the prex to be valid for on-link determination with no time limit.
• lifetime {preferred-lifetime seconds | infinite} — (Optional) Sets AdvPreferredLifetime in seconds
for the prex in the radvd.conf le. IPv6 addresses generated from the prex using stateless autoconguration remain preferred
for the congured lifetime. The default is 14400 seconds (4 hours). The
infinite setting allows addresses that are
autocongured using the prex to be preferred with no time limit.
By default, all prexes congured in IPv6 addresses on an interface are advertised. To modify the default values advertised for
interface subnet prexes, 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.
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