Setting ags in IPv6 router advertisement messages
An IPv6 router advertisement message can include the following ags:
• Managed Address Conguration--This ag indicates to hosts on a local link if they should use the stateful autoconguration
feature to get IPv6 addresses for their interfaces. If the ag is set, the hosts use stateful autoconguration to get addresses as
well as non-IPv6-address information. If the ag is not set, the hosts do not use stateful autoconguration to get addresses and
if the hosts can get non-IPv6-address information from stateful autoconguration is determined by the setting of the Other
Stateful Conguration ag.
• Other Stateful Conguration--This ag indicates to hosts on a local link if they can get non-IPv6 address autoconguration
information. If the ag is set, the hosts can use stateful autoconguration to get non-IPv6-address information.
NOTE
When determining if hosts can use stateful autoconguration to get non-IPv6-address information, a set Managed Address
Conguration ag overrides an unset Other Stateful Conguration ag. In this situation, the hosts can obtain nonaddress
information. However, if the Managed Address Conguration ag is not set and the Other Stateful Conguration ag is set, then
the setting of the Other Stateful Conguration ag is used.
By default, the Managed Address Conguration and Other Stateful Conguration ags are not set in router advertisement messages. For
example, to set these ags in router advertisement messages sent from Ethernet interface 1/3/1, enter the following commands.
device(config)#interface ethernet 1/3/1
device(config-if-e1000-1/3/1)#ipv6 nd managed-config-flag
device(config-if-e1000-1/3/1)#ipv6 nd other-config-flag
Syntax: [no] ipv6 nd
managed-cong-ag
Syntax: [no] ipv6 nd other-cong-ag
To remove either ag from router advertisement messages sent on an interface, use the no form of the respective command.
Enabling and disabling IPv6 router advertisements
If IPv6 unicast routing is enabled on an Ethernet interface, by default, this interface sends IPv6 router advertisement messages. However,
by default, non-LAN interface types, for example, tunnel interfaces, do not send router advertisement messages.
To disable the sending of router advertisement messages on an Ethernet interface, enter commands such as the following.
device(config)#interface ethernet 1/3/1
device(config-if-e1000-1/3/1)#ipv6 nd suppress-ra
To enable the sending of router advertisement messages on a tunnel interface, enter commands such as the following.
device(config)#interface tunnel 1
device(config-tnif-1)#no ipv6 nd suppress-ra
Syntax: [no] ipv6 nd suppress-ra
IPv6 router advertisement preference support
IPv6 router advertisement (RA) preference enables IPv6 RA messages to communicate default router preferences from IPv6 routers to
IPv6 hosts in network topologies where the host has multiple routers on its Default Router List. This improves the ability of the IPv6
hosts to select an appropriate router for an
o-link destination.
IPv6 neighbor discovery conguration
FastIron Ethernet Switch Layer 3 Routing
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