RIPng enabled on PC1, Router1, Router2
Router2 has a static IPv6 DG ( Default Gateway ) to InternetGateway
Router1 has no static IPv6 DG, and no kernel{learn} directive.

Router2=Ubuntu14.04 LTS, Router1=raspbian Wheezy, bird = last version,
compiled from sources
link-local addresses replaces with symbolic names ( ie [fe80::Router1] )

May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: Initializing
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1: Initializing
May 3 12:06:19 vubuntu-VirtualBox bird6: device1: Initializing
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1: Initializing
May 3 12:06:19 vubuntu-VirtualBox bird6: device1: Starting
May 3 12:06:19 vubuntu-VirtualBox bird6: device1: Scanning interfaces
May 3 12:06:19 vubuntu-VirtualBox bird6: device1: Connected to table master
May 3 12:06:19 vubuntu-VirtualBox bird6: device1: State changed to feed
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: Starting
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: Connected to table master
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: State changed to feed
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1: Starting
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1: Connected to table master
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1: State changed to feed
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1: Starting
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1: Listening on (dummy), port 521, mode broadcast (::)
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1: Connected to table master
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1: State changed to feed
May 3 12:06:19 vubuntu-VirtualBox bird6: Started
May 3 12:06:19 vubuntu-VirtualBox bird6: device1: State changed to up
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1 < interface lo goes up
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1 < interface eth0 goes up
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1 < interface eth1 goes up
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: State changed to up
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1 < primary address ::1/128 on interface lo added
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1 < primary address 2001:db8:0:1::/64 on interface eth0 added
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1 > added [best] 2001:db8:0:1::/64 dev eth0
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1 < rejected by protocol 2001:db8:0:1::/64 dev eth0
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1 < added 2001:db8:0:1::/64 dev eth0
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1 < secondary address fe80::/64 on interface eth0 added
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1 < primary address 2001:db8:0:5::/64 on interface eth1 added
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1 > added [best] 2001:db8:0:5::/64 dev eth1
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1 < rejected by protocol 2001:db8:0:5::/64 dev eth1
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1 < added 2001:db8:0:5::/64 dev eth1
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1 < secondary address fe80::/64 on interface eth1 added
May 3 12:06:19 vubuntu-VirtualBox bird6: direct1: State changed to up
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1 < interface lo goes up
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1 < interface eth0 goes up
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1 < interface eth1 goes up
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1 < added 2001:db8:0:1::/64 dev eth0
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1 < added 2001:db8:0:5::/64 dev eth1
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1: State changed to up
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: Scanning routing table
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: ::/0: [alien] created
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: Pruning table master
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1: Pruning inherited routes
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1 > added [best] ::/0 via 2001:db8:0:1::1 on eth0
May 3 12:06:19 vubuntu-VirtualBox bird6: kernel1 < rejected by protocol ::/0 via 2001:db8:0:1::1 on eth0
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1 < added ::/0 via 2001:db8:0:1::1 on eth0
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1: Listening on eth1, port 521, mode multicast (ff02::9)
May 3 12:06:19 vubuntu-VirtualBox bird6: rip1: Listening on eth0, port 521, mode multicast (ff02::9)
May 3 12:06:21 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:21 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:22 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:22 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:22 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: ::/0 available, metric 16...
May 3 12:06:22 vubuntu-VirtualBox bird6: rip1 > added [best] ::/0 via fe80::[Router1] on eth1
May 3 12:06:22 vubuntu-VirtualBox bird6: kernel1 < added ::/0 via fe80::[Router1] on eth1
May 3 12:06:22 vubuntu-VirtualBox bird6: rip1 < forced accept by protocol ::/0 via fe80::[Router1] on eth1
May 3 12:06:22 vubuntu-VirtualBox bird6: rip1 < replaced ::/0 via fe80::[Router1] on eth1
May 3 12:06:22 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: 2001:db8:0:1::/64 available, metric 16...
May 3 12:06:22 vubuntu-VirtualBox bird6: rip1 > added 2001:db8:0:1::/64 via fe80::[Router1] on eth1
May 3 12:06:23 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: ::/0 available, metric 16...
May 3 12:06:23 vubuntu-VirtualBox bird6: rip1 > ignored ::/0 via fe80::[Router1] on eth1
May 3 12:06:23 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: 2001:db8:0:1::/64 available, metric 16...
May 3 12:06:23 vubuntu-VirtualBox bird6: rip1 > ignored 2001:db8:0:1::/64 via fe80::[Router1] on eth1
May 3 12:06:23 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:23 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:24 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: ::/0 available, metric 16...
May 3 12:06:24 vubuntu-VirtualBox bird6: rip1 > ignored ::/0 via fe80::[Router1] on eth1
May 3 12:06:24 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:24 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:25 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:25 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:25 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: ::/0 available, metric 16...
May 3 12:06:25 vubuntu-VirtualBox bird6: rip1 > ignored ::/0 via fe80::[Router1] on eth1
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: ::/0 available, metric 16...
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1 > ignored ::/0 via fe80::[Router1] on eth1
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: 2001:db8:0:1::/64 available, metric 16...
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1 > ignored 2001:db8:0:1::/64 via fe80::[Router1] on eth1
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: 2001:db8:0:3::/64 available, metric 1...
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1 > added [best] 2001:db8:0:3::/64 via fe80::[Router1] on eth1
May 3 12:06:26 vubuntu-VirtualBox bird6: kernel1 < added 2001:db8:0:3::/64 via fe80::[Router1] on eth1
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1 < forced accept by protocol 2001:db8:0:3::/64 via fe80::[Router1] on eth1
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1 < added 2001:db8:0:3::/64 via fe80::[Router1] on eth1
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: 2001:db8:0:5::/64 available, metric 1...
May 3 12:06:26 vubuntu-VirtualBox bird6: rip1 > added 2001:db8:0:5::/64 via fe80::[Router1] on eth1
May 3 12:06:27 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:27 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:28 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:28 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:29 vubuntu-VirtualBox bird6: device1: Scanning interfaces
May 3 12:06:29 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:29 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:30 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:30 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:31 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:31 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:32 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:32 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:33 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:33 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:34 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:34 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:35 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:35 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:36 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:36 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:37 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:37 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:38 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:38 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:39 vubuntu-VirtualBox bird6: device1: Scanning interfaces
May 3 12:06:39 vubuntu-VirtualBox bird6: kernel1: Scanning routing table
May 3 12:06:39 vubuntu-VirtualBox bird6: kernel1: 2001:db8:0:3::/64: seen
May 3 12:06:39 vubuntu-VirtualBox bird6: kernel1: ::/0: [alien] seen
May 3 12:06:39 vubuntu-VirtualBox bird6: kernel1: ::/0: seen
May 3 12:06:39 vubuntu-VirtualBox bird6: kernel1: Pruning table master
May 3 12:06:39 vubuntu-VirtualBox bird6: kernel1: Pruning inherited routes
May 3 12:06:39 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:39 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:40 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:40 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:41 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:41 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:42 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:42 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:43 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:43 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:44 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:44 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:45 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:45 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:46 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:46 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:47 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:47 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:48 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:48 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:49 vubuntu-VirtualBox bird6: device1: Scanning interfaces
May 3 12:06:49 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:49 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:50 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:50 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:51 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:51 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:52 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:52 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:53 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:53 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:54 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:54 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:55 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:55 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:56 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:56 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: ::/0 available, metric 16...
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1 > ignored ::/0 via fe80::[Router1] on eth1
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: 2001:db8:0:1::/64 available, metric 16...
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1 > ignored 2001:db8:0:1::/64 via fe80::[Router1] on eth1
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: 2001:db8:0:3::/64 available, metric 1...
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1 > ignored 2001:db8:0:3::/64 via fe80::[Router1] on eth1
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1: block: fe80::[Router1] tells me: 2001:db8:0:5::/64 available, metric 1...
May 3 12:06:57 vubuntu-VirtualBox bird6: rip1 > ignored 2001:db8:0:5::/64 via fe80::[Router1] on eth1
May 3 12:06:58 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:58 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:59 vubuntu-VirtualBox bird6: device1: Scanning interfaces
May 3 12:06:59 vubuntu-VirtualBox bird6: kernel1: Scanning routing table
May 3 12:06:59 vubuntu-VirtualBox bird6: kernel1: 2001:db8:0:3::/64: seen
May 3 12:06:59 vubuntu-VirtualBox bird6: kernel1: ::/0: [alien] seen
May 3 12:06:59 vubuntu-VirtualBox bird6: kernel1: ::/0: seen
May 3 12:06:59 vubuntu-VirtualBox bird6: kernel1: Pruning table master
May 3 12:06:59 vubuntu-VirtualBox bird6: kernel1: Pruning inherited routes
May 3 12:06:59 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:59 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:06:59 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:06:59 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:07:00 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:07:00 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1
May 3 12:07:01 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth0
May 3 12:07:01 vubuntu-VirtualBox bird6: rip1: Broadcasting routing table to eth1

2001:db8:0:1::/64 dev eth0 proto kernel metric 256
2001:db8:0:3::/64 via fe80::[Router1] dev eth1 proto bird metric 1024
2001:db8:0:5::/64 dev eth1 proto kernel metric 256
fe80::/64 dev eth0 proto kernel metric 256
fe80::/64 dev eth1 proto kernel metric 256
default via 2001:db8:0:1::1 dev eth0 proto static metric 1
default via fe80::[Router1] dev eth1 proto bird metric 1024

router id 192.168.5.1;
protocol kernel {
learn;
scan time 20;
export all;
import all;
}

protocol rip {
debug all;
port 521;
interface "*" { mode multicast; ttl security on; };
honor neighbor;
authentication none;

import all;
export all;
}
---------------------------------------------------------------------------

On Apr 29, 2015 4:30 PM, <pavel.tvrdik@nic.cz> wrote:

Hi Olivier,

I failed to reproduce the metric 1024. Can you please send a log file from Router2?

On 2015-04-29 11:02, olivier a wrote:

Follow up : Nobody has ideas about that ?
On Apr 18, 2015 7:14 PM, "olivier a" <oatech7402@gmail.com> wrote:
>
> Hello all ^^
>
> I'm puzzled with a really weird RIPng default gateway propagation
problem.
> I don't quite understand what's happening. Here is what happens ...
>
> Network topology :
>
> PC1---Router1---Router2----InternetGateway---z
>
> RIPng enabled on PC1, Router1, Router2
> Router2 has a static IPv6 DG ( Default Gateway ) to InternetGateway
> Router1 has no static IPv6 DG, and no kernel{learn} directive.
>
> Router2=Ubuntu14.04 LTS, Router1=raspbian Wheezy, bird = last
version, compiled from sources
> link-local addresses replaces with symbolic names ( ie
[fe80::Router1] )
>
> Something really strange seems to happen :
>
> . Router2 gets this routing table :
>
> default via InternetGateway dev eth0 proto static metric 1
> default via [fe80::Router1] dev eth1 proto bird metric 1024

Did you try commented out the learn directive in protocol kernel? Did the metric 1024 disappear?

>
> But Router1 isn't announcing any IPv6 DefaultGateway, just ::/0
metric 16 ( ie it is poisoning the route ).
> ( I checked using Wireshark ).
>
> Is there a bug that transforms a received "::/0 metric 16" into a
"default via [fe80::Router1] dev eth1 proto bird metric 1024" route
?

Probably not.

>
> Here is Router2 bird6.conf file :
>
> -------------------------------------------------
> log syslog all;
> debug protocols all;
> #log stderr all;
> #log "tmp" all;
>
> router id 192.168.4.1;
> protocol kernel {
> learn;
> scan time 20;
> export all;
> import all;
> }
>
> protocol direct {
> #interface "eth0";
> }
>
> protocol device {
> scan time 10;
> }
>
> protocol rip {
> debug all;
> port 521;
> interface "*" { mode multicast; ttl security on; };
> honor neighbor;
> authentication none;
> import all;
> export all;
> }
> -------------------------------------------------------------
>
> I managed to solve the problem, by having Router2 drop incomming
::/0 announcements :
>
> ---------------------------------------------------------
> import filter { # This block filters ::/0 in
> if net ~ [ ::/0 ] then
> reject "ripng:rejected:DG";
> else
> accept "ripng:accepted:not-DG";
> };
>
> export all;

Do you use filter at rip or at kernel protocol?

>
> ---------------------------------------------------------
>
> the problem is solved, yet it puzzles me.
> This is really strange. Does anybody understand what is happening
??

Pavel