Connectivity Guide

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.
Congure neighbor discovery
OS10(config)# interface ethernet 1/1/1
OS10(conf-if-eth1/1/1)# ipv6 nd mtu 1500
OS10(conf-if-eth1/1/1)# ipv6 nd send-ra
Congure advertised IPv6 prexes
OS10(config)# interface ethernet 1/1/1
OS10(conf-if-eth1/1/1)# ipv6 nd prefix default lifetime infinite infinite
OS10(conf-if-eth1/1/1)# ipv6 nd prefix 2002::/64
Duplicate address discovery
To determine if an IPv6 unicast address is unique before assigning it to an interface, an OS10 switch sends a neighbor solicitation message.
If the process of duplicate address discovery (DAD) detects a duplicate address in the network, the address does not congure on the
interface. DAD is enabled by default.
By default, IPv6 is not disabled when a duplicate address is detected. Only the duplicate address is not applied. Other IPv6 addresses are
still active on the interface.
To disable IPv6 on an interface when a duplicate link-local address is detected, use the ipv6 nd dad disable-ipv6-on-failure
command. To re-enable IPv6 after you resolve a duplicate link-local address, enter no ipv6 enable, then the ipv6 enable
command.
• Disable or re-enable IPv6 duplicate address discovery in Interface mode.
ipv6 nd dad {disable | enable}
• Disable IPv6 on an interface if a duplicate link-local address is discovered in Interface mode.
ipv6 nd dad disable-ipv6-on-dad-failure
Layer 3
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