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auto-dad (SLAAC Snooping)


Hierarchy Level


Configure parameters for Duplicate Address Detection (DAD) to be performed by the SLAAC snooping device. DAD is used by IPv6 clients to verify the uniqueness of addresses obtained through stateless address auto-configuration (SLAAC). DAD sends a Neighbor Solicitation message destined to the new address. If there is a reply, then the address is a duplicate; if the address is unique, it is assigned to the interface.

If DAD is disabled on the client side, or if DAD packets are dropped due to traffic congestion, the SLAAC snooping device can perform auto-DAD on the client’s behalf. You can configure the number of times that DAD will attempt to verify the address and the length of time that DAD waits for a response before retransmission. The client address binding remains in a hold state until all transmissions are completed.


retries retry-count

Configure the number of times that auto-DAD sends a Neighbor Solicitation message to verify the uniqueness of an address obtained through SLAAC.

retrans-interval seconds

Configure the interval between retransmissions of a Neighbor Solicitation message for auto-DAD.

Required Privilege Level

interface—To view this statement in the configuration.

interface-control—To add this statement to the configuration.

Release Information

Statement introduced in Junos OS Release 19.2R1.