ndppd.conf.5.adoc

ndppd.conf(5) Manual Page

Name

ndppd.conf - ndppd configuration file

Description

This file is used to describe which interfaces to proxy as well as which rules must match in order to respond to any neighbor solicitation messages. Most of the configuration options are simple key-value pairs, with the exceptions being proxy and rule which must also include a block containing additional configuration options.

A most basic example of this is valid-ttl with a configured value of 10000 milliseconds.

valid-ttl 10000

Which options are valid depends on the block in which they are defined. The example above is allowed at top level, but would not be allowed inside a rule or a proxy block. Please see Options for details regarding valid configuration options. In order for the ndppd.conf to be valid, at least one proxy must be defined. An in each of these proxies, at least one rule must be defined.

In short; the general structure of ndppd.conf can be simplified to:

...

route eth0 {
    rule dead:beef:: {
        ...
    }
}

Comments

ndppd.conf supports two types of comments.

C-style

/* This is a comment */

Python

# This a comment

Options

Top-level

valid-ttl milliseconds

The time a target will be considered valid after having received a neighbor advertisement from a neighbor.

Default: 30000

invalid-ttl milliseconds

The time a target will be considered invalid after not receiving any neighbor solicitation messages from a neighbor.

Default: 5000

retrans-time milliseconds

The time ndppd will wait before sending another neighbor solicitation to the internal interface.

Default: 1000

retrans-limit count

How many times ndppd attempt to send neighbor solicitation messages, and not receiving a valid neighbor advertisement response, before considering it being invalid.

Default: 3

proxy interface block

Create a new proxy on the specified interface. That interface will be listening for neighbor solicitation messages and then reply with neighbor advertisement messages if the conditions were met.

proxy eth0 {
    # Proxy specific configuration
}

Proxy specific

rule ip [ / prefix ] block

Add a new rule for the matching IPv6 address. If prefix is not specified, it defaults to 128. Note that the address and prefix must be provided without any whitespace between them.

rule dead:beef::1/127 {
    # Route specific configuration
}

Rule specific

auto

If specified, ndppd will attempt to automatically determine where to forward Neighbor Solicitation messages. This feature uses the Netlink protocol.

static

Automatically respond. This option is mutually exclusive with iface and auto.

iface interface

Forwards the Neighbor Solicitation message through this specific interface.

autowire

A flag whether or not a new route should be automatically added to the routing table if a match has been found.

table index

Indicates which routing table should be used when auto and autowire is used.