control/diagnose IPv6 Neighbor Discovery Protocol
-c | -p]
-P | -R]
command manipulates the address mapping
table used by the Neighbor Discovery Protocol (NDP).
- Repeat -a (dump NDP entries)
every wait seconds.
- Dump the currently existing NDP entries. The following
information will be printed:
- The IPv6 address of the neighbor.
- Linklayer Address
- The linklayer address of the neighbor. If the address
is not available, it will be displayed as
- The network interface associated with the neighbor
- The time until expiry of the entry. If the entry is
marked “permanent”, it will never expire.
- The state of the neighbor cache entry, as a single
- Unknown state (should never happen).
- Flags on the neighbor cache entry, in a single letter.
They are: local (‘l’), Router (‘R’) and proxy
neighbor advertisement (‘p’). This field may be followed
by a decimal number, representing the number of NS probes the node has
sent during the current state.
- Erase all the NDP entries.
- Delete the specified NDP entry.
- Parse entries from file to
be inserted in the neighbor cache. See the -s
option for a description of the file format.
- Harmonize consistency between the routing table and the
default router list; install the top entry of the list into the kernel
- View ND information for the specified interface. If
additional arguments are given, ndp sets or
clears the specified flags for the interface. Each flag should be
separated by whitespace or tab characters. Possible flags are as follows.
All of the flags can begin with the special character
-’, which means the flag should be
cleared. Note that -- would be needed before
-foo in this case.
- Turn on or off NUD (Neighbor Unreachability Detection)
on the interface. NUD is usually turned on by default.
- Specify whether or not to accept Router Advertisement
messages received on the interface.
Note that the kernel does not accept Router Advertisement messages
unless the interface is configured for inet6 autoconfiguration.
- Do not try to resolve numeric addresses to hostnames.
- Flush all the entries in the prefix list.
- Show the prefix list.
- Flush all the entries in the default router list.
- Show the default router list.
- Register an NDP entry for the node called nodename with the
Ether address ether_addr. The Ethernet address is given as six hexadecimal
bytes separated by colons. The entry will be permanent unless the word
temp is given in the command. If the word
proxy is given, this system will act as an ND
Proxy server, responding to requests for
nodename even though the node address is
not its own.
- Print a timestamp on each entry, making it possible to
merge output with
tcpdump(8). Most useful
when used with -A.
- Select the routing domain.
utility exits 0 on success,
and >0 if an error occurs.
command first appeared in the WIDE
Hydrangea IPv6 protocol stack kit.