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Table of Contents >> IPv6 Programmer's Reference

#include <trsocket.h>

int tfSetReachable (
struct sockaddr_storage * addrPtr,
ttUserInterface interface,
int * reachableMsecPtr

Function Description

Applications call this function periodically to notify Neighbor Unreach-ability Detection of the reach-ability of a peer node. Essentially, this allows applications to "refresh" the ARP cache entry that is used when sending to the peer. [RFC 2461]


  • addrPtr
    IP address of a peer node that the application has received reach-ability confirmation for in the form of "forward progress"; it could be a neighbor, or a remote node reachable through router(s). If the peer node is a neighbor, the reach-ability for the neighbor will be set to REACHABLE, otherwise the reach-ability for the first-hop router in the path to the peer node is set to REACHABLE.
  • interface
    Only needed when addrPtr is an IPv6 local scope address. This identifies the outgoing interface that the address specified by addrPtr is reachable through.
  • reachableMsecPtr
    Output parameter; if not NULL, then the new reachable time (in milliseconds) of the matching ARP cache entry will be stored here on return.


    addrPtr was NULL, or addrPtr points to a local scope IPv6 address but interface was invalid.
    No ARP entry exists for the specified peer IP address; send some packets first to the peer to cause the ARP entry to be created.

Table of Contents >> IPv6 Programmer's Reference