Man pages › Compared with Linux and the BSDs

`ndp(8)` on Solnix vs Linux and the BSDs

On Solnix, ndp is the illumos ndp at /usr/sbin/ndp. It shows and edits the IPv6 neighbor table, but it is much smaller than the BSD ndp: -a just runs netstat -p -f inet6, and there is no -c, -p, -r, -t or -V. Entries made with -s take the keywords temp, any and router, not proxy.

The manual pages

Solnix: ndp(8) from pkgs.solnix.illumos-world-man · illumos.org
FreeBSD: ndp(8) 15.1-RELEASE
OpenBSD: ndp(8) 8.0
NetBSD: ndp(8) 11.0

What Solnix runs

A default Solnix system runs the illumos ndp at /usr/sbin/ndp. No other variants are shipped. Changing the table with -d, -s or -f needs the PRIV_SYS_NET_CONFIG privilege.

Differences

Compared with	Topic	What differs
FreeBSD, OpenBSD, NetBSD	`-a` implementation	On Solnix, ndp `-a` is documented as equivalent to `netstat `-p` `-f` inet6`, and `-n` is passed on to netstat. The BSD pages describe `-a` as ndp's own dump with Neighbor, Linklayer Address, Netif, Expire, S and Flags columns. Source: Solnix ndp(8) -a; FreeBSD ndp(8) -a; OpenBSD ndp(8) -a; NetBSD ndp(8) -a
FreeBSD, OpenBSD, NetBSD	`-c` erase all entries	Solnix ndp has no `-c`. The FreeBSD, OpenBSD and NetBSD pages use `-c` to erase all NDP entries. On Solnix, delete entries one at a time with `-d` hostname. Source: Solnix ndp(8) SYNOPSIS; FreeBSD ndp(8) -c; OpenBSD ndp(8) -c; NetBSD ndp(8) -c
FreeBSD, OpenBSD, NetBSD	`-s` keywords	Solnix `-s` takes `lladdr [temp] [any] [router]`. The BSD pages take `etheraddr [temp] [proxy]`. Solnix has no proxy keyword; any marks an anycast address and router marks a router address. The manual does not say how to proxy on Solnix. Source: Solnix ndp(8) SYNOPSIS, -s; FreeBSD ndp(8) SYNOPSIS; OpenBSD ndp(8) -s; NetBSD ndp(8) -s
FreeBSD, OpenBSD, NetBSD	`-s` replaces the flag set	On Solnix, the flags listed on `-s` are the full set wanted. Leaving one out removes it from an existing entry. To make a static entry temporary, delete and recreate it with temp. The BSD pages do not say this. Source: Solnix ndp(8) -s; FreeBSD ndp(8) -s; OpenBSD ndp(8) -s; NetBSD ndp(8) -s
FreeBSD, NetBSD	`-i` meaning	On Solnix, `-i` iface only forces the interface for a mapping, and is ignored with `-a` or `-A`. On FreeBSD and NetBSD, `-i` interface [expressions] views per-interface ND information and can set flags such as nud, disabled and curhlim. Solnix has none of these. Source: Solnix ndp(8) -i; FreeBSD ndp(8) -i; NetBSD ndp(8) -i
OpenBSD	`-i` on OpenBSD	On OpenBSD, `-i` interface views ND information for that interface. On Solnix, `-i` selects which interface a mapping is placed on. Source: Solnix ndp(8) -i; OpenBSD ndp(8) -i
FreeBSD, OpenBSD, NetBSD	`-t` timestamps	Solnix ndp has no `-t`. FreeBSD, OpenBSD and NetBSD use `-t` to print a timestamp on each entry for merging output with tcpdump(8). Source: Solnix ndp(8) SYNOPSIS; OpenBSD ndp(8) -t; NetBSD ndp(8) -t
FreeBSD	prefix, router and default interface	Solnix ndp has no `-p` (prefix list), `-r`, `-H`, `-P`, `-R` or `-I`. FreeBSD ndp has all of these for prefixes, routers and the default interface. The Solnix manual does not say where to get this on Solnix. Source: Solnix ndp(8) SYNOPSIS; FreeBSD ndp(8) SYNOPSIS, -p, -H, -I
OpenBSD	routing domain	OpenBSD ndp `-V` rdomain selects the routing domain. Solnix ndp has no equivalent option. Source: OpenBSD ndp(8) -V; Solnix ndp(8) SYNOPSIS
FreeBSD, OpenBSD, NetBSD	`-a` state names	Solnix `-a` documents entry types (dynamic, local, other, static) and states spelled out: INCOMPLETE, REACHABLE, STALE, DELAY, PROBE, UNREACHABLE, UNKNOWN. The BSD pages document single-letter state codes. The NetBSD page also has U for Unreachable. Parsers of one format will not read the other. Source: Solnix ndp(8) -a; FreeBSD ndp(8) -a (S column); OpenBSD ndp(8) -a; NetBSD ndp(8) -a
FreeBSD, OpenBSD, NetBSD	`-n` and DNS	Solnix `-n` disables translating numeric addresses to host names. OpenBSD adds that an unresolvable name without DNS gives an error. The Solnix page does not say this. Source: Solnix ndp(8) -n; OpenBSD ndp(8) -n
FreeBSD, OpenBSD, NetBSD	exit status	OpenBSD and NetBSD document exit 0 on success and non-zero (OpenBSD: >0) on error. The Solnix page has no EXIT STATUS section, so the manual does not say. Source: OpenBSD ndp(8) EXIT STATUS; NetBSD ndp(8) EXIT STATUS; Solnix ndp(8)

Standards

POSIX: ndp is not a POSIX.1-2024 utility.

Writing portable scripts

Do not rely on -c, -t, -p or the -i expressions: they exist only on some BSDs. Delete entries by name with -d hostname.
Do not parse ndp -a output across systems. Solnix gives netstat -p -f inet6 output, and the BSDs print their own columns with single-letter states.

Every difference here is taken from the manual pages linked above: Solnix's published page, Linux (man-pages and the GNU and util-linux manuals), FreeBSD, OpenBSD and NetBSD. Each row names its source. Where a manual is silent, this page is too. Compiled 2026-10-26. Found a mistake? Mail hackers@lists.solnix.io.