Configuring IPv6 RA

Procedure
  1. Enable transmission of IPv6 router advertisements with the commandno ipv6 nd suppress-ra.
  2. Optionally, configure IPv6 unicast address prefixes with the commandipv6 nd prefix.
  3. Optionally, configure support for DNS name resolution with the commandsipv6 nd ra dns serverandipv6 nd ra dns search-list.
  4. 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
  5. Review IPv6 RA configuration settings with the commandsshow ipv6 nd interface,show ipv6 nd interface prefix,show ipv6 nd ra dns server, andshow ipv6 nd ra dns search-list.

Example

This example creates the following configuration:

  • Enables IPV6 RA on interface1/1/3.

  • Sets the recursive DNS server address to4001::1with a lifetime of400seconds.

  • Sets the minimum interval between transmissions to3seconds.
  • Sets the maximum interval between transmissions to13seconds.

  • 设置一个默认的路由器的一生1900seconds.

switch(config)#interface 1/1/3switch(config)#no ipv6 nd suppress-raswitch(config-if)#ipv6 nd ra dns server 4001::1 lifetime 400switch(config-if)#ipv6 nd ra min-interval 3switch(config-if)#ipv6 nd ra max-interval 13switch(config-if)#ipv6 nd ra lifetime 1900switch(config-if)#endswitch#show ipv6 nd interface 1/1/3Interface 1/1/3 is up Admin state is up IPv6 address: 2006::1/64 [VALID] IPv6 link-local address: fe80::98f2:b321:368:6dc6/64 [VALID] ICMPv6 active timers: Last Router-Advertisement sent: 0 Secs Next Router-Advertisement sent in: 13 Secs Router-Advertisement parameters: Periodic interval: 3 to 13 secs Router Preference: medium Send "Managed Address Configuration" flag: false Send "Other Stateful Configuration" flag: false Send "Current Hop Limit" field: 64 Send "MTU" option value: 1500 Send "Router Lifetime" field: 1900 Send "Reachable Time" field: 0 Send "Retrans Timer" field: 0 Suppress RA: false Suppress MTU in RA: true ICMPv6 error message parameters: Send redirects: false ICMPv6 DAD parameters: Current DAD attempt: 1 switch#show ipv6 nd ra dns server递归DNS Server List on: 1/1/3 Suppress DNS Server List: No DNS Server 1: 2001::1 lifetime 400