Configuring IPv6 RA
Procedure
- Enable transmission of IPv6 router advertisements with the command no ipv6 nd suppress-ra.
- Optionally, configure IPv6 unicast address prefixes with the command ipv6 nd prefix.
- Optionally, configure support for DNS name resolution with the commands ipv6 nd ra dns server and ipv6 nd ra dns search-list.
- For most deployments, the default values for the following features do not need to be changed. If your deployment requires different settings, change the default values with the indicated command:
IPv6 RA setting
Default value
Command to change it
Number of neighbor solicitations to be sent when performing DAD.
1
ipv6 nd dad attempts
Number of neighbor entries in the ND cache.
131072
ipv6 nd cache-limit
Hop limit to be sent in the RA messages.
64
ipv6 nd hop-limit
MTU value to be sent in the RA messages.
1500 bytes
ipv6 nd mtu
Neighbor solicitation interval
1000 milliseconds
ipv6 nd ns-interval
Lifetime of a default router.
1800 seconds
ipv6 nd ra lifetime
Retrieval of an IPv6 address by devices.
Disabled
ipv6 nd ra managed-config-flag
Maximum interval between transmissions of IPv6 RAs.
600 seconds
ipv6 nd ra max-interval
Minimum interval between transmissions of IPv6 RAs.
200 seconds
ipv6 nd ra min-interval
Time that an interface considers a device to be reachable.
0 milliseconds (no limit)
ipv6 nd ra reachable-time
Retry period between ND solicitations.
0 (Use locally configured NS-interval)
ipv6 nd ra retrans-timer
Default routing preference for an interface.
Medium
ipv6 nd router-preference
- Review IPv6 RA configuration settings with the commands show ipv6 nd interface, show ipv6 nd interface prefix, show ipv6 nd ra dns server, and show ipv6 nd ra dns search-list.
Example
On the 6400 Switch Series, interface identification differs.
This example creates the following configuration:
- Enables IPV6 RA on interface 1/1/3.
- Sets the recursive DNS server address to 4001::1 with a lifetime of 400 seconds.
- Sets the minimum interval between transmissions to 3 seconds.
- Sets the maximum interval between transmissions to 13 seconds.
- Sets the lifetime of a default router to 1900 seconds.