[Dibbler] Hello quick question about dibbler and openbsd

Tomasz Mrugalski thomson at klub.com.pl
Thu Sep 20 19:16:44 CEST 2012


On 20.09.2012 16:29, Sly Midnight wrote:
> I do have some questions about the original or Linux specific script. 
> What is the purpose of the following variables in the script?
> 
> $OPTION_NEXT_HOP
> $OPTION_NEXT_HOP_RTPPREFIX
> $OPTION_RTPPREFIX
They should be set if route-options are used. There is a draft in IETF
(draft-ietf-mif-route-option-05) that allows configuration of routing
information. NEXT_HOP contains router address, RTPREFIX contains prefix
available on-link and NEXT_HOP_RTPREFIX contains a prefix that is
available via router and that router's address. That's essentially all
information required to configure a prefix.

See section 4.4 of Dibbler User's Guide for more details and examples.

> In my copy of the script I actually have not modified those lines at
> all, they are still Linux specific.  But I have not seen them called, so
> I do not yet understand what they are supposed to be doing.  I added
> lines that merely call ifconfig with the correct syntax to add addresses
> to the appropriate interfaces and then I use a somewhat clumsy approach
> to adding the DNS servers.  I am still thinking of a better way to add
I'm not sure if adding DNS servers is really needed. Dibbler-client is
supposed to add DNS servers and domain names to /etc/resolv.conf. The
implementation is in Port-bsd/lowlevel-options-bsd.c in function
dns_add(). It is very simple and should work. OpenBSD keeps resolve.conf
in /etc, right?

> the DNS servers as the dhclient script for the IPv4  version overwrites
> the changes I make, so this is not ideal.
There's a tool that is called resolvconf. It is being used in Debian.
I'm not sure if it is Debian-specific, Linux-specific or also available
on BSDs.

There's --enable-resolvconf parameter for enabling it on Linux version.
It will not work on BSD out of the box, but copying those changes should
be a simple copy of the code marked with #ifdef MOD_RESOLVCONF
from Port-linux/lowlevel-options-linux.c to
Port-linux/lowlevel-options-bsd.c.

> Also currently I have no way of getting dibbler (at least on OpenBSD) to
> setup the default route for IPv6.  If the IP address for the default
That is protocol limitation. DHCPv6 as it is defined today does not
allow configuring that. There's that working draft in IETF that I've
mentioned. It is currently unclear if it will proceed forward and will
become published as RFC (many people want that) or be abandoned (other
people want that to happen). Dibbler supports it, but


> route could be obtained and passed via the notify script I could easily
> set it up with a route add command.
See scripts/notify-scripts/client-notify-linux.sh and the usage of
NEXT_NOP and RTPREFIX options. It uses ip tool that is Linux specific,
but you'll get the idea easily.

Tomek



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