13-15The maximum interval for sending RA messages should be less than or equal to the router lifetime inRA messages.Configuring the Maximum Number of Attempts to Send an NS Message for DADAn interface sends a neighbor solicitation (NS) message for duplicate address detection after acquiringan IPv6 address. If the interface does not receive a response within a specified time (determined bythe ipv6 nd ns retrans-timer command), it continues to send an NS message. If it still does notreceive a response after the number of sent attempts reaches a configurable threshold, the acquiredaddress is considered usable.Follow these steps to configure the attempts to send an NS message for DAD:To do… Use the command… RemarksEnter system view system-view —Enter interface view interface interface-typeinterface-number —Configure the number ofattempts to send an NSmessage for DADipv6 nd dad attempts valueOptional1 by default. When the valueargument is set to 0, DAD isdisabled.Configuring PMTU DiscoveryConfiguring a Static PMTU for a Specified IPv6 AddressYou can configure a static PMTU for a specified destination IPv6 address. When a source host sends apacket through an interface, it compares the interface MTU with the static PMTU of the specifieddestination IPv6 address. If the packet size is larger than the smaller one between the two values, thehost fragments the packet according to the smaller value.Follow these steps to configure a static PMTU for a specified address:To do… Use the command… RemarksEnter system view system-view —Configure a static PMTU for aspecified IPv6 addressipv6 pathmtu ipv6-address[ value ]RequiredBy default, no static PMTU isconfigured.Configuring the Aging Time for Dynamic PMTUsAfter the path MTU from a source host to a destination host is dynamically determined (refer to IPv6PMTU Discovery), the source host sends subsequent packets to the destination host on basis of this
