[Dibbler] Relay Configuration Problem

Tomasz Mrugalski thomson at klub.com.pl
Tue May 3 12:39:29 CEST 2005

On Tue, 3 May 2005 somebody known as Jimmy Ott wrote:

> i've got problems while configure Relay in following network topology.
> http://www.sunny.ch/downloadfiles/ipv6_workshop.jpg
> the routing between the different subnets works, at the moment the
> clients recieve the prefix from the routers R1, R2, R3
> i've set up the the dibbler server, and now, if i'm right their should
> be two relays in the client subnets, is that correct? but how should i
Basically, there are two ways:
- configure relays on R1 and R2 and have them forward traffic directly to
   the NS1 using unicast adress.
   * Main advantage: only 2 relays.
   * Main disadvantage: statically configured global address.
- configure relays on R1 and R2 and have them forward traffic using
   multicast. That traffic will be received by the additional relay
   configured on R3, which will forward it to the NS1 server.
   * Main advantage: this will work after network renumbering.
   * Main disadvantage: 3 relays needs to be deployed.

> configure them? i DO NOT have 2 interfaces in the relay, is it possible
> to activate server multicast and client multicast on the same interface,
> and how do i have to edit the server.conf on dhcpv6 server which also
> have only one interface?
The preferred way is to install dibbler-relay on the routers (R1 and R2). 
You can have them communicate using unicast directly to the NS1. However, 
this might be a problem, if your routers are hardware routers.

It is a theoretically possible to install relay on a one interface node. 
It would receive local client messages and relay them to the remote server 
using unicast. But such configuration was never tested. You could try 
config files similar to those provided below.

# relay.conf
log-level 8
iface eth2 {
# server multicast yes      // relay messages on this interface to ff05::1:3
   server unicast 6000::10   // relay messages on this interface to this global address
   client multicast yes      // bind ff02::1:2
   interface-id 1234

# server.conf
log-level 8
iface relay1 // relay1 - name of the logical interface (not present in the system)
  relay eth0  // is uses real interface eth0
  interface-id 1234
  class {
         pool 2000::10-2000::ff

Also make sure to use an ustable version as it contains important fixes 
for several issues related to the relays. It is able to handle rather 
similar situation, so I expect you could make it work for you, too. Take a 
look at the following network diagram: 
Config files (2-*.conf) provided in the 0.4.0-CVS version 
(http://klub.com.pl/dhcpv6/dibbler/dibbler-0.4.0-CVS-linux.tar.gz) are 
provided to relay traffic over 2 relays.

Hope that helps

Tomasz Mrugalski,              | "I think there is a world market for     |
thomson(at)klub(dot)com(dot)pl |  about five computers."                  |
                                |     Thomas J. Watson (Chairman, IBM) 1943|

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