default route problem

[e2rd at piekielko.pl]

Hi,
I've got very simple config:
-- bird.conf --
log "/var/log/bird.log" { debug, trace, info, remote, warning, error, auth, fatal, bug };
debug protocols all;
router id 172.0.0.1;
protocol kernel {
     learn;
     persist;
     scan time 20;
     export all;
}
protocol device {
     scan time 10;
}
protocol static {
     route 0.0.0.0/0 drop;
}
protocol ospf MyOSPF {
     export all;
     area 0.0.0.0 {
         interface "dummy*" {
         };
     };
     area 10.0.0.0 {
         nssa;
         interface "eth*" {
             type nbma;
         };
     };
}
-- end --

If area 10.0.0.0 is commented it works as expected:

bird> s o l

Global

  Type   LS ID           Router           Age  Sequence  Checksum
  0005  192.168.54.255  172.0.0.1           3  80000001    c588
  0005  192.168.55.0    172.0.0.1           3  80000001    ba92
  0005  0.0.0.0         172.0.0.1           3  80000001    cb22
  0005  10.155.74.255   172.0.0.1           3  80000001    cc31

Area 0.0.0.0

  Type   LS ID           Router           Age  Sequence  Checksum
  0001  172.0.0.1       172.0.0.1           2  80000001    ac9b
bird>

but if I uncomment it (area 10) default route is disapearing:
bird> sh ro
0.0.0.0/0          blackhole [static1 01:34] ! (200)
                    via 10.5.2.1 on eth0 [kernel1 23:50] (10)
10.5.2.0/24        dev eth0 [MyOSPF 23:51] * I (150/10) [172.0.0.1]
10.155.74.0/24     via 10.155.74.5 on tun0 [kernel1 23:50] * (10)
192.168.54.0/24    via 10.155.74.5 on tun0 [kernel1 23:50] * (10)
192.168.55.0/24    via 10.155.74.5 on tun0 [kernel1 23:50] * (10)
172.0.0.1/32       dev dummy0 [MyOSPF 23:51] * I (150/0) [172.0.0.1]
bird> s o l

Global

  Type   LS ID           Router           Age  Sequence  Checksum
  0005  192.168.54.255  172.0.0.1           2  80000001    c588
  0005  192.168.55.0    172.0.0.1           2  80000001    ba92
  0005  10.155.74.255   172.0.0.1           2  80000001    cc31

Area 0.0.0.0

  Type   LS ID           Router           Age  Sequence  Checksum
  0001  172.0.0.1       172.0.0.1           1  80000001    af97
  0003  10.5.2.255      172.0.0.1           1  80000001    e2b1

Area 10.0.0.0

  Type   LS ID           Router           Age  Sequence  Checksum
  0001  172.0.0.1       172.0.0.1           1  80000001    22b7
  0003  172.0.0.1       172.0.0.1           1  80000001    847d
bird>

If the area 10.0.0.0 is stub or nssa default route is propagated in ospf.

After changing area 10 to normal area and reconfiguring bird log says:

<TRACE> MyOSPF: Going to remove LSA Type: 0005, Id: 0.0.0.0, Rt: 172.0.0.1, Age: 3600, Seqno: 0x7fffffff

<TRACE> MyOSPF: Flushing AS-external-LSA for 0.0.0.0/0
<TRACE> MyOSPF: Flushing summary-LSA (id=0.0.0.0, type=3)
<TRACE> MyOSPF: Going to remove LSA Type: 0003, Id: 0.0.0.0, Rt: 172.0.0.1, Age: 3600, Seqno: 0x7fffffff
<TRACE> MyOSPF: Flushing AS-external-LSA for 0.0.0.0/0


Why 0.0.0.0/0 is removed from ospf while other kernel routes not?
How redistribute it in multiple areas?

other info:
localhost:/tmp# ip ro sh
10.155.74.5 dev tun0  proto kernel  scope link  src 10.155.74.6
10.155.74.0/24 via 10.155.74.5 dev tun0
192.168.54.0/24 via 10.155.74.5 dev tun0
192.168.55.0/24 via 10.155.74.5 dev tun0
10.5.2.0/24 dev eth0  proto kernel  scope link  src 10.5.2.2
default via 10.5.2.1 dev eth0

lo: 127.0.0.1/8
eth0: 10.5.2.2/24
tun0: 10.155.74.6 peer 10.155.74.5/32
dummy0: 172.0.0.1/32


regards,

--
Łukasz