NDP(8) OpenBSD System Manager's Manual NDP(8)NAMEndp - control/diagnose IPv6 Neighbor Discovery Protocol (NDP)
SYNOPSISndp [-nrt] [-a | -c | -p] [-H | -P | -R] [-A wait] [-d hostname]
[-f filename] [-I [interface | delete]] [-i interface [flag ...]] [-s
nodename etheraddr [temp] [proxy]] [hostname]
DESCRIPTION
The ndp command manipulates the address mapping table used by the
Neighbor Discovery Protocol (NDP).
-A wait
Repeat -a (dump NDP entries) every wait seconds.
-a Dump the currently existing NDP entries. The following
information will be printed:
Neighbor
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
``(incomplete)''.
Netif The network interface associated with the neighbor
cache entry.
Expire The time until expiry of the entry. If the entry is
marked ``permanent'', it will never expire.
S The state of the neighbor cache entry, as a single
letter:
D Delay
I Incomplete
N Nostate
P Probe
R Reachable
S Stale
W Waitdelete
? Unknown state (should never happen).
Flags Flags on the neighbor cache entry, in a single letter.
They are: 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.
-c Erase all the NDP entries.
-d hostname
Delete the specified NDP entry.
-f filename
Parse the file specified by filename.
-H Harmonize consistency between the routing table and the default
router list; install the top entry of the list into the kernel
routing table.
-I Shows the default interface used as the default route when there
is no default router.
-I interface
Specifies the default interface to be used when there is no
interface specified even though required.
-I delete
The current default interface will be deleted from the kernel.
-i interface [flag ...]
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.
nud Turn on or off NUD (Neighbor Unreachability Detection) on
the interface. NUD is usually turned on by default.
accept_rtadv
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
net.inet6.ip6.accept_rtadv variable is non-0, even if the
flag is on. This flag is set to 1 by default. See
sysctl(8) and sysctl.conf(5) for further details on how
to set the net.inet6.ip6.accept_rtadv variable.
-n Do not try to resolve numeric addresses to hostnames.
-P Flush all the entries in the prefix list.
-p Show the prefix list.
-R Flush all the entries in the default router list.
-r Show the default router list.
-s nodename etheraddr [temp] [proxy]
Register an NDP entry for a node. 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 a proxy NDP server, responding
to requests for hostname even though the host address is not its
own.
-t Print a timestamp on each entry, making it possible to merge
output with tcpdump(8). Most useful when used with -A.
EXIT STATUS
The ndp utility exits 0 on success, and >0 if an error occurs.
SEE ALSOip6(4), sysctl.conf(5), arp(8), sysctl(8), tcpdump(8)HISTORY
The ndp command first appeared in the WIDE Hydrangea IPv6 protocol stack
kit.
OpenBSD 4.9 September 3, 2010 OpenBSD 4.9
