ndpd-router Daemon

Purpose

NDP and RIPng daemon for a router.

Syntax

ndpd-router [ -r] [ -p] [ -M] [ -O] [ -s] [ -q] [ -g] [ -n] [ -R] [ -S] [ -d] [ -t] [ -v] [ -H ] [ -m ] [ -u port] [ -D max[min[/life]]] [ -P [invlife]/[deplife]] [ -T [reachtim]/[retrans]/[hlim]] [ -e [ off | compatible | only ] ]

Description

The ndpd-router daemon manages the Neighbor Discovery Protocol (NDP) for non-kernel activities. It receives Router Solicitations and sends Router Advertisements. It can also exchange routing information using the RIPng protocol.

The /etc/gateway6 file provides options for ndpd-router. This file can be modified while the program is running. The changes are checked before any emission or reception of message, or on reception of the HUP signal. The file contains directives, one by line (with # as comment). All the IPv6 addresses and prefixes in the file must be in numeric form. No symbolic name is allowed. Except for the gateway directive, each line begins with a keyword and is made of options of the form key=argument.

Interfaces

The ndpd-router daemon knows about IEEE and CTI point to point interfaces. The ndpd-router daemon exchanges packets on all the known interfaces UP with a Link-Local Address. Any change of status of an interface is detected. If an interface goes down or loses its Link-Local address, the NDP and RIPng processing is stopped on this interface. If an interface goes up, the NDP and RIPng processing is started.

To send Router Advertisements or RIPng packets or both, local and remote Link-Local addresses must be configured.

Flags

Available directives

The option directive

Sets different per-interface options.

Syntax:

option [ if=n1,n2 ] ripin=(y|n),ripout=(y|n|S|R),rtadv=(y|n|min[/max]),flag=[M|O],life=Seconds,reach=Seconds,retrans=Seconds

The prefix directive

Defines the prefixes announced in Router advertisement directives. If there is no prefix-directive for an interface, the router advertisement contains the list of prefixes deduced from the address list of the interface. If there are prefix-directives, the router advertisement contains the list of prefixes defined by the different prefix directives (in order). No prefix is installed in the kernel. If there is one directive of the form prefix prefix=none, no prefix list is advertised.

Syntax:

prefix if=n prefix=(none|xxx::/PrefixLength) flag=[L][A] valid=Seconds deprec=Seconds

The filter directive

Define a filter pattern for incoming (filter=in) or outgoing (filter=out) RIPng packets. There is one incoming and one outgoing filter per interface, and one default incoming and one default outgoing filter for interfaces without explicit filter.

Any received RIPng information is tested against the input filter of the interface, or, if there is none, against the default input filter. The static interface routes are seen as input information coming from the interface and from a gateway with the link local address of the interface. The routes set by a gateway directive with a gateway keyword are seen as input information coming from the specified interface and gateway. The default route (-g flag) and the routes set by a gateway directive without a gateway keyword are seen as input information coming from gateway :: and no interface (the default input filter applies).

Any sent RIPng information is tested against the output filter of the interface, or, if there is none, against the default output filter.

Each filter is a sequence of matching patterns. The patterns are tested in order. Each pattern can test the prefix length, the source gateway (for input filters and that the prefix (padded with zeroes) matches a fixed prefix. If a pattern contains more than one test description, the match is the conjunction of all the tests. The first matching pattern defines the action to perform. If no pattern matches, the default action is accept. The possible actions are accept, reject and truncate/NumberOfBits. The truncate/NumberOfBits action means: if the pattern matches and if prefix length is greater or equal to NumberOfBits, accept the prefix with new length NumberOfBits. The accepted prefix is immediately accepted, that is, not checked again against the filters.

filter=out length==128 action=reject

Syntax:

filter=(in|out) [if=n1,n2] prefix=xx::/NumberOfBits gateway=xxx length=(=|>=|<=|<|>)NumberOfBits action=(accept|reject|truncate/xx)

Gateway directives

The gateway directives allow the user to set up routes in RIPng packets and/or in the kernel. These directives must appear at the end of the /etc/gateway6 file, after the other directives.

Syntax:

xxx::/NumberOfBits metric Value

xxx::/NumberOfBits metric Value gateway IPv6Address ifname

The second syntax is used to add the route to the kernel.

Examples

The following examples are of the /etc/gateway6 file.

On a site where all addresses are of the form 5f06:2200:c001:0200:xxxx, the following example means that only one route, describing all the site, is exported on all the Configured Tunnel Interface (CTI) ctiX interfaces. The keyword abbreviations shown are valid.

filt=out if=cti* pref=5f06:2200:c001:0200::/64 len=>=64 act=trunc/64

Setting a default outgoing route:

::/0 metric 2 gateway 5f06:2200:c102:0200::1 cti0

Declare that any CTI interface active with RIPng defines a default route:

filter=in if=cti* act=trunc/0

The following example defines a site with an exterior connection cti0, which aggregates other sites connected through ctiX, and which uses split horizon without poisoned reverse. The order of the lines is important, as all filter descriptions apply to cti0.

option if=cti* ripout=R
filter=out if=cti0 prefix=5f06:2200::/24 len=>=24 act=trunc/24
filt=out if=cti* pref=5f06:2200:c001:0200::/64 len=>=64 act=trunc/64
filter=in if=cti0 act=trunc/0
filter=in if=cti* prefix=5f06:2200::/24 len=>=24 act=trunc/64
filter=in if=cti* act=reject

Diagnostics

All errors are logged at the daemon.err level, unless the debug option is set. This includes all the syntax errors in the /etc/gateway6 file and configuration mismatches between different routers.

Signals

ndpd-router responds to the following signals:

Files