---
name: "rrenumd.conf"
section: "5"
platform: "freebsd"
package: "base"
version: "16.0-CURRENT-20261027-61c70dc16a79"
release: "FreeBSD 16.0-CURRENT (2026-10-27)"
platforms: ["freebsd"]
url: "https://new.carta.tech/rrenumd.conf"
---

# rrenumd.conf(5)

configuration file for router renumbering daemon

## NAME

**rrenumd.conf** – configuration file for router renumbering daemon

## DESCRIPTION

The rrenumd config file describes how the router renumbering packet must be constructed and to which destinations it should be sent. This file consists of a sequence of statements terminated by a semi-colon (\`;'). Statements are composed of tokens separated by white space, which can be any combination of blanks, tabs and newlines. This structure simplifies identification of the parts of the configuration associated with each other. Lines beginning with ‘#’ are comments.

## Meta Syntax

Keywords and special characters that the parser expects exactly are displayed using the **bold** font. Parameters are specifying with *underline*. Parameters shown in square brackets (\`\[' and \`\]') are used to show optional keywords and parameters. The vertical bar (\`\|') is used to indicate between a choice of optional parameters. Curly braces (\`{' and \`}') are used to group keywords and parameters when necessary.

## Interface specification

There are some statements that may or have to specify interface. Interfaces are specified in the form of "name unit", such as *lo0* and *ep1*.

## Configuration Statements

- **debug** **on\|off**;

  Enables configuration file parser debugging. If **on** is specified, then debugging is enabled, If **off** is specified, then debugging is disabled. It is disabled by default.

- **dest** *dest-list* \[*retrycmd*\];

  Specifies destinations to which router renumbering messages should be sent. *dest-list* can be any combination of single or multiple numerical IPv6 addrs, or Full Qualified Domain Names. *retrycmd* has following syntax.

  - **retry** *retry-num*

    *retry-num* specifies how many router renumbering messages are sent repeatedly.

- \[**add\|change\|setglobal**\]

  **match-prefix** *match-prefix-val* \[/match-prefix-len\] \[**maxlen** *maxlen-val*\] \[**minlen** *minlen-val*\] \[**use-prefix** *use-prefix-val*\] \[/use-prefix-len\] \[**keeplen** *keeplen-val*\] \[*use-prefix-values*\];

  Specifies contents of sending router renumbering message with seqnum 0. If **add\|change\|setglobal** is not specified, then **add** is assumed. *use-prefix-values* has following syntax.

  { \[**vltime** *vltime-val*\] \[**pltime** *pltime-val*\] \[**raf\_onlink** **on\|off**\] \[**raf\_auto** **on\|off**\] \[**rrf\_decrprefd** **on\|off**\] \[**rrf\_decrvalid** **on\|off**\] }

  Each value has following meaning.

  - **match-prefix** *match-prefix-val* \[/match-prefix-len\]

    Specify *match-prefix-val* that is used for matching with preassigned prefixes to which **add\|change\|setglobal** command should be applied. */match-prefix-len* Specify the starting part of *match-prefix-val* to be used for matching with preassigned prefixes, as decimal bit number.

  - **maxlen** *maxlen-val*

    Specify the maximum length of prefixes which is allowed to be matched to *match-prefix-val*, as decimal bit number.

  - **minlen** *minlen-val*

    Specify the minimum length of prefixes which is allowed to be matched to *match-prefix-val*, as decimal bit number.

  - **use-prefix** *use-prefix-val* \[/usr-prefix-len\]

    Specify *use-prefix-val* that is used for prefixes to be added on **add\|change\|setglobal** command. */use-prefix-len* Specify the starting part of *use-prefix-val* copied to the starting part of prefixes to be added on **add\|change\|setglobal** command, as decimal bit number.

  - **keeplen** *keeplen-val*

    Specify the medium part of *use-prefix-val* just next to the starting part specified by *use-prefix-len*, as decimal bit number. Contiguous bits part in the same bit position of an existent prefix matched with *match-prefix-val* is copied to the same bit position of prefixes to be added.

  - **vltime** *vmtime-val*

    Assign an *time* as prefix valid life time for a prefix to be added. Valid value for *time* is decimal seconds number or special format as "d00h00m00s00", where 00 can take any decimal number, and "d" means days, "h" means hours, "m" means minutes, "s" means seconds. And alternatively, special keyword "infinity" can be also be specified.

  - **pltime** *pltime-val*

    Assign an *time* as prefix preferred life time for a prefix to be added. Valid value for *time* is same as for *vltime-val*.

  - **raf\_onlink** **on\|off**

    Let the prefix to be added to have on-link or off-link nature for the assigned interface. If **on** is specified, the prefix have on-link nature (e.g. the prefix belong to the link). If **off** is specified, the prefix have off-link nature (e.g. the prefix does not belong to the link).

  - **raf\_auto** **on\|off**

    Enable or disable the autonomous address auto configuration for the prefix to be added. If **on** is specified, autonomous address auto configuration is enabled. If **off** is specified, it is disabled.

  - **rrf\_decrprefd** **on\|off**

    Enable or disable the decrementation of the pltime. If **on** is specified, decrementation of the pltime is enabled. If **off** is specified, decrementation of the pltime is disabled.

  - **rrf\_decrvalid** **on\|off**

    Enable or disable the decrementation of the vltime. If **on** is specified, decrementation of the vltime is enabled. If **off** is specified, decrementation of the vltime is disabled.

- seqnum *seqnum-val* *{* *rrenum-cmd* *}*;

  Specifies contents of sending router renumbering message with some specific seqnum. Multiple of this statement can be specified if they have different *seqnum-val* each other. *rrenum-cmd* has just same syntax with above add\|change\|setglobal statement.

## EXAMPLES

For each configuration file example shown below, we suppose every IPv6 subnet has its own prefix beginning with fec0:0:0::/48 and with its own subnet number (in this case, subnet number is 7th and 8th octet value of the prefix).

If you want to assign prefixes beginning with 3ffe:501:ffff::/48 to each subnet, then following configuration will be enough, if each of your routers supports IPv6 multicast forwarding. The subnet number of the existing fec0:0:0::/48 prefix and the newly assigned 3ffe:501:ffff::/48 prefix will be same.

```
dest ff05::2;
add match-prefix fec0:0:0:: /48 use-prefix 3ffe:501:ffff:: /48 keeplen 16;
```

If your routers do not support IPv6 multicast forwarding, you will need to specify each destination at **dest** command.

```
dest fec0:0:0:1:260:8ff:fe24:fb3a fec0:0:0:2:200:eff:fe2e:dfe1 fec0:0:0:3:5254:ff:fedc:5217;
add match-prefix fec0:0:0:: /48 use-prefix 3ffe:501:ffff:: /48 keeplen 16;
```

If you are going to do renumbering, then following procedure will be natural.

1. Assign a new prefix.

2. Set old prefix lifetimes to some appropriate transition period. In the following example we use 1 week for valid lifetime, and 0 for preferred lifetime. Also, enable old prefix lifetime expiration (By default, it is static and does not expire).

3. After the transition period, old prefixes should become invalid, and may have been deleted. To make sure that they are deleted, send new router renumbering message, which specifies old prefixes as match prefix, and no use prefix.

The following configuration file will do 1 and 2.

```
dest ff05::2;
seqnum 0 {
	add match-prefix fec0:0:0:: /48 use-prefix 3ffe:501:fffe:: /48 keeplen 16;
	};
seqnum 1 {
	change match-prefix 3ffe:501:ffff:: /48 use-prefix 3ffe:501:ffff:: /48 keeplen 16 vltime d7 pltime 0 rrf_decrvalid on rrf_decrprefd on;
	};
```

And the following configuration file will do 3 (should be used for the router renumbering message to be sent 1 week afterward).

```
dest ff05::2;
change match-prefix 3ffe:501:ffff:: /48;
```

In the above example, only **add** and **change** commands are used, and there is no example for **setglobal** command. **setglobal** command is almost same with **change** command except that it deletes all pre-defined IPv6 global address.

## SEE ALSO

prefix(8), [rrenumd(8)](/rrenumd/8.md)

## HISTORY

The **rrenumd.conf** configuration file was first appeared in KAME IPv6 protocol stack kit.