[Dibbler] dibbler server don't receive client solicit message

Radek Zajíc radek at zajic.v.pytli.cz
Wed Jun 18 21:10:03 CEST 2014


Dear all,

having the same issue, I did some further investigation. The firewall is
not the problem (wide-dhcpv6 works), neither is an apparmor (uninstalled
that piece of... and rebooted).

The configuration is really simple, however does not work with dibbler. It
does work with wide-dhcp6, though.

First I was considered that dibbler may be affected by this issue:
http://www.spinics.net/lists/netdev/msg286344.html
So I installed the latest kernel 3.15.0-031500-generic (testing on Ubuntu
14.04) - the problem still exists.

The latest thought I have is that dibbler is affected as mentioned here:
http://serverfault.com/questions/590558/ubuntu-14-04-ipv6-multicast
"This behavior was not present in kernel versions below 3.10, which
apparently didn't handle node-local multicast properly. See the actual
kernel patch that enforces this and the function definition of
__ipv6_addr_needs_scope_id."

So I did further tests. Installed Ubuntu 13.10 with default kernel and
settings - and Dibbler (0.8.2-1) works.
Installed Ubuntu 14.04 with default kernel and settings - and Dibbler
(1.0.0~rc1-1) does not respond.

So I upgraded kernel in Ubuntu 13.10 to 3.14.1-031401-generic and Dibbler
(0.8.2-1) does not respond anymore.

It seems there have really been kernel changes that broke/changed the
multicast handling, breaking Dibbler completely.

To all of you who have problem with Dibbler, what kernel version are you
using?

Thanks
Radek

=== dumps & info ===

# tcpdump -i br0.2 '(udp port 546)||(udp port 547)' -n
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on br0.2, link-type EN10MB (Ethernet), capture size 65535 bytes
# dibbler responses (missing)
16:22:26.251241 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
16:22:26.397952 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
16:22:26.573567 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
16:22:27.615026 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
16:22:29.601133 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit

# wide-dhcpv6 responses (correct)
16:23:29.616639 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
16:23:29.616871 IP6 fe80::922b:34ff:fed1:ed8.49872 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 advertise
16:23:29.617412 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
request
16:23:29.617556 IP6 fe80::922b:34ff:fed1:ed8.49872 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 reply
16:23:57.083111 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
confirm
16:23:57.083308 IP6 fe80::922b:34ff:fed1:ed8.49872 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 reply
16:23:58.104311 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
confirm
16:23:58.104472 IP6 fe80::922b:34ff:fed1:ed8.49872 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 reply
16:23:59.116940 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
confirm
16:23:59.117112 IP6 fe80::922b:34ff:fed1:ed8.49872 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 reply

==== Dibbler configuration ====
# cat /etc/dibbler/server.conf
log-level 8
preference 0
iface "br0.2" {
 // also ranges can be defines, instead of exact values
 t1 1800-2000
 t2 2700-3000
 prefered-lifetime 3600
 valid-lifetime 7200
 class {
    pool 2a01:8c00:ff44::1000/96
 }
 ta-class {
    pool 2a01:8c00:ff44::2000/96
 }
 option dns-server 2a01:8c00:ff44::127
}

# dpkg --list|grep dibbler
ii  dibbler-doc
1.0.0~rc1-1                                         all
documentation for Dibbler
ii  dibbler-server
1.0.0~rc1-1                                         amd64        portable
DHCPv6 server

# ip -6 maddr show dev br0.2
6:      br0.2
        inet6 ff02::1:2
        inet6 ff02::1:ff00:2
        inet6 ff02::fb
        inet6 ff02::1:ff00:0 users 2
        inet6 ff02::1:ffd1:ed8
        inet6 ff02::1:ff00:1
        inet6 ff02::2 users 2
        inet6 ff02::1
        inet6 ff01::1

==== wide-dhcpv6-server ====
# cat /etc/wide-dhcpv6/dhcp6s.conf
option domain-name-servers      2a01:8c00:ff44::127;
option domain-name              "dira.lan";

interface br0.2 {
    address-pool br02 3600;
};

pool br02 {
    range 2a01:8c00:ff44::1000 to 2a01:8c00:ff44::2000;
};

# dpkg --list|grep wide-dhcp
ii  wide-dhcpv6-server
20080615-12                                         amd64        DHCPv6
server for automatic IPv6 hosts configuration

# ip -6 maddr show dev br0.2
6:      br0.2
        inet6 ff05::1:3
        inet6 ff02::1:2
        inet6 ff02::1:ff00:2
        inet6 ff02::fb
        inet6 ff02::1:ff00:0 users 2
        inet6 ff02::1:ffd1:ed8
        inet6 ff02::1:ff00:1
        inet6 ff02::2 users 2
        inet6 ff02::1
        inet6 ff01::1

============== Ubuntu 13.10 with linux-image-3.11.0-12-generic
======================
20:57:13.467201 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
20:57:13.467685 IP6 fe80::5054:ff:fe05:c0d1.547 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 advertise
20:57:13.497322 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
20:57:13.498217 IP6 fe80::5054:ff:fe05:c0d1.547 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 advertise
20:57:13.671613 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
20:57:13.672369 IP6 fe80::5054:ff:fe05:c0d1.547 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 advertise
20:57:14.668986 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
20:57:14.669696 IP6 fe80::5054:ff:fe05:c0d1.547 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 advertise
20:57:16.668977 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
20:57:16.669683 IP6 fe80::5054:ff:fe05:c0d1.547 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 advertise
20:57:16.895300 IP6 fe80::5054:ff:fe05:c0d1.546 > ff02::1:2.547: dhcp6 renew
20:57:20.684582 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
20:57:20.685098 IP6 fe80::5054:ff:fe05:c0d1.547 >
fe80::e48a:3505:cf50:bb27.546: dhcp6 advertise

============== Ubuntu 13.10 with 3.14.1-031401-generic
======================
21:04:06.376502 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
21:04:06.414278 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
21:04:06.440153 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
21:04:07.454272 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
21:04:09.455268 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
21:04:13.457167 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit
21:04:21.461210 IP6 fe80::e48a:3505:cf50:bb27.546 > ff02::1:2.547: dhcp6
solicit




On Fri, May 30, 2014 at 5:11 PM, George Joseph <george.joseph at fairview5.com>
wrote:

> On Fri, May 30, 2014 at 3:52 AM, Tomasz Mrugalski <thomson at klub.com.pl>
> wrote:
>
>> On 30.05.2014 10:42, amysue.z at gmail.com wrote:
>> > I have installed dibbler 0.84 on centos 6.3 32bit. The pc has received
>> > client solicit message, verified by wireshark. But dibbler server don't,
>> > and no advertise message send.
>> > I have no idea what to do now, could any one help me.
>> Check your firewall. Wireshark is doing raw packet capture on wire, so
>> it bypasses firewall. Dibbler opens regular UDP socket, so it is
>> affected by a firewall.
>>
>> Two things to check: ip6tables and apparmor.
>>
>> Tomek
>>
>> Funny...I have the exact same problem on Fedora 20.  I had previously run
> dibbler with no issues but switched back to "dhcpd -6" for a while.   When
> I tried dibbler again last week (same binary as the earlier working
> install), it acted as though it wasn't receiving packets and I had to go
> back to "dhcpd -6".    I did upgrade from Fedora 19 to 20 in the mean time
> so I'm wondering if something in the environment is causing the problem.
>  dhcpd IS working though.
>
>
>
>
>
>
>
>
> _______________________________________________
> http://klub.com.pl/cgi-bin/mailman/listinfo/dibbler
>
>
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