Re: Generic neighbour manipulatoin

Alexey Kuznetsov (
Mon, 7 Dec 1998 16:41:58 +0300 (MSK)


/default/ are default values, which are copied to
any newly created device. They may be overriden by device
driver or manually.

All these variables and neighbour state machine
are superbly described in IPv6 NDISC RFC
(f.e. new one appeared last week, I forgot number)

* mcast_solicit

Number of broadcast ARPs (or multicast NDISC probes)
before neighbour is considered unreachable.

* ucast_solicit

If address is known, linux periodically probes neighbour
with unicast ARPs. If ucast_solicit requests are not answered,
it falls to broadcasting.

* app_solicit

If not zero and CONFIG_ARPD is defined, request is sent to user level
daemon before broadcasting to network.

* retrans_time

Interval between probes.

* unres_qlen

Maximal number of packets in queue of unresolved packets.

* gc_stale_time

Unused entries are removed after this period.

* base_reachable_time

reachable_time := random number in the interval

If for this time no neighbour reachibility confirmations
(f.e. from TCP) were received, the entry is marked as STALE.

* delay_first_probe_time

If entry is STALE, the first attempt to send data
to the neighbour starts timer delay_first_probe_time.
If no neighbour reachibility confirmations will arrive
during this timeout, we will start unicast probes.

* locktime

[ ARP/IPv4 specific ] When an entry is modified,
it is locked for period "locktime", so that attempts
to change it during this time are ignored.

* anycast_delay

[ IPv6 specific ] Maximal delay before answering to request for
anycast address.

* proxy_delay

Maximal delay before sending proxy ARP reply.

* proxy_qlen

Maximal number of requests, waiting in proxy arp queue.

Alexey Kuznetsov

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