The ARP module maintains a cache of mappings between hard- ware addresses and protocol addresses. The cache has a limited size so old and less frequently used entries are garbage-collected. Entries which are marked as permanent are never deleted by the garbage-collector. The cache can be directly manipulated by the use of ioctls and its behaviour can be tuned by the sysctls defined below. If that fails too it will broad- cast a new ARP request to the network.
Requests are only send when there is data queued for sending.
When there is a reject route for the target no proxy arp entry is added. They take a pointer to a struct arpreq as their parameter. Unless otherwise specified time related sysctls are specified in seconds. The maximum number of jiffies to delay before replying to a IPv6 neighbour solicitation message. Anycast support is not yet implemented.