Fwd: Received route with strange next-hop

[Christian Kölpin]

Hello Community

First I have to say, the problem occurs in a lab/soho environment, so it
might be unusal to normal bird purposes.

I'am running two routers who uses bird/OSPF to exchange their routing
tables. One router represents the firewall and "internet-connection",
the second runs several VPN daemons (IPSec, OpenVPN, L2TP). Some foreign
Routers are connected via these VPNs and running OSPF as well (mix
quagga/bird). All is running well except some "stange next-hop"
messages. The Problem is, I don't understand why i get these messages.
To me, the routes looks ok. So I don't understand the problem at all.
Maybe someone can help me to understand it.

OS: linux/openwrt
Bird: version 1.3.3

I have two "problematic" routes who leads to "strange next-hop" messages:
1) network: 192.168.100.128 gateway 192.168.100.130 netmask
255.255.255.128 (/25)
bird-message: KRT: Received route 192.168.100.128/25 with strange
next-hop 192.168.100.130
add info: the network is a OpenVPN "Roadwarrior"-network. There is a
tun0-ptp-interface with 192.168.100.129 as local an 192.168.100.130 as
foreign address

2) network 0.0.0.0 (default) gateway 84.57.128.1 netmask 0.0.0.0
bird-message: KRT: Received route 0.0.0.0/0 with strange next-hop
84.57.128.1
add info: the default route is injected by the pppd when the router
connects to my german-isp via pppoe (DSL). I have a ptp-interface with
my dynamic ip an the GW-address as foreign address

Both gateways are listed in the kernel-routing as directly connected via
a /32 route (eg 84.57.128.1 gw 0.0.0.0 netmask 255.255.255.255)

If I start the BIRD instances on both routers and the problematic routes
are present in the kernel table, all works well. No Messages, the routes
are "learned" trough the "kernel-protocol", handed over to the
OSPF-protocol and propagated to the other routers. All is fine. But if
the ISP forcing a reconnect (its a contract without static ip) or the
openvpn-daemon needs to restart, the problem starts.

The mentioned messages appears in syslog and no routes are learned and
propagated. I get around this, whit defining some stub-networks in ospf
or a static-default route.

Interesting fact: even if a DON'T put activate the kernel learn-switch
and set explicit import to none i get these message. I have to set the
kernel scan-time to 0 to suppress continuous log-spamming with the message.

protocol kernel {
        export all;
        import none;
        scan time 0;
}

So what I'm doing wrong? How can I connect bird and ptp-interfaces the
right way?

greetings
Raptor 2101