Why filter not work for two cases?

[Владислав Гришин]

My network.

Bird is used as border router on the standalone server.

I have a two upstream ISPs from which I accept full view + default route
over eBGP.
I have a one downstream ISP to which I announce full view + default route.

Into my AS a IGP protocol is OSPF.  The L3 switch Cisco 3550 is used on a
network.
Bird IP is 10.10.1.2, Cisco 3550 IP is 10.10.1.3.

To BGP downstream I plan to announce a default route which is exported from
the bird static protocol, for stability.
For OSPF neighbors I plan to announce a default route which is received from
the upstream ISPs, since for each operator in the future there will be a
server.

Now the default route in routing table is imported only from upstreams,
route to 0.0.0.0/0 network is not present in static protocol of bird.

Оutput of birdc

bird> show route where source=RTS_BGP && net = 0.0.0.0/0
0.0.0.0/0          via 93.191.9.205 on eth2.701 [bgpfiord 2010-05-09
19:37:35] * (100) [AS28917i]
                   via 82.138.44.129 on eth2.51 [bgpcomcor 2010-05-09
19:37:31] (100) [AS8732i]
bird>

bird> show route where net = 0.0.0.0/0
0.0.0.0/0          via 93.191.9.205 on eth2.701 [bgpfiord 2010-05-09
19:37:35] * (100) [AS28917i]
                   via 82.138.44.129 on eth2.51 [bgpcomcor 2010-05-09
19:37:31] (100) [AS8732i]
bird>

The filter which exports a default route from routing table to OSPF protocol
looks as follows

...

filter export_default_route_from_bgp_to_ospf {
    if ( source = RTS_BGP && net = 0.0.0.0/0 ) then {
        print "net accepted:", net;
        ospf_metric1 = 48;
        accept;
    }
    reject;
}
...

Default route is present в LSA_DB of OSPF bird. See output of birdc

bird> show ospf lsadb

Global

 Type   LS ID           Router           Age  Sequence  Checksum
 0005  0.0.0.0         10.10.1.2          41  80000001    a16c
 0005  11.11.11.12     10.10.1.3        1880  80000037    9f88
 0005  12.12.12.12     10.10.1.3        1880  80000037    7ba9
 0005  13.13.13.12     10.10.1.3        1880  80000037    57ca

Area 0.0.0.0

 Type   LS ID           Router           Age  Sequence  Checksum
 0001  10.10.1.2       10.10.1.2         125  80000129    19a8
 0001  10.10.1.3       10.10.1.3          93  8000018a    cf76
 0002  10.10.1.3       10.10.1.3          94  80000006    7ed6
bird>


Console output of 3550

3550-L3-S1#show ip route 0.0.0.0
Routing entry for 0.0.0.0/0, supernet
  Known via "ospf 65500", distance 110, metric 49, candidate default path,
type extern 1
  Last update from 10.10.1.2 on Vlan550, 00:00:39 ago
  Routing Descriptor Blocks:
  * 10.10.1.2, from 10.10.1.2, 00:00:39 ago, via Vlan550
      Route metric is 49, traffic share count is 1

3550-L3-S1#

Default route is present в LSA_DB of OSPF Cisco 3550.

Now I add a command in a configuration of the static protocol

protocol static {
...
        route 0.0.0.0/0 via "lo";
...
}

I softly restart bird and see the following

bird> show route where source=RTS_BGP && net = 0.0.0.0/0
0.0.0.0/0          via 93.191.9.205 on eth2.701 [bgpfiord 2010-05-09
19:37:35] (100) [AS28917i]
                   via 82.138.44.129 on eth2.51 [bgpcomcor 2010-05-09
19:37:31] (100) [AS8732i]
bird>
bird> show route where net = 0.0.0.0/0
0.0.0.0/0          dev lo [static1 2010-05-09 20:12:32] * (254)
                   via 93.191.9.205 on eth2.701 [bgpfiord 2010-05-09
19:37:35] (100) [AS28917i]
                   via 82.138.44.129 on eth2.51 [bgpcomcor 2010-05-09
19:37:31] (100) [AS8732i]
bird>

Default route is not present в LSA_DB of OSPF bird.

Оutput of birdc

bird> show ospf lsadb

Global

 Type   LS ID           Router           Age  Sequence  Checksum
 0005  11.11.11.12     10.10.1.3         246  80000038    9d89
 0005  12.12.12.12     10.10.1.3         246  80000038    79aa
 0005  13.13.13.12     10.10.1.3         246  80000038    55cb

Area 0.0.0.0

 Type   LS ID           Router           Age  Sequence  Checksum
 0001  10.10.1.2       10.10.1.2         519  80000129    19a8
 0001  10.10.1.3       10.10.1.3         487  8000018a    cf76
 0002  10.10.1.3       10.10.1.3         488  80000006    7ed6
bird>

In result OSPF neighbor Cisco 3550 does not receive default route from bird.

3550-L3-S1#show ip route 0.0.0.0
% Network not in table
3550-L3-S1#

Сlause "source = RTS_BGP && net = 0.0.0.0/0" in filter
export_default_route_from_bgp_to_ospf and clause "source=RTS_BGP && net =
0.0.0.0/0" in the "show route" command is same.

Why the default route is not exported to OSPF protocol from bird routing
table after adding 

route 0.0.0.0/0 via "lo"; 

in bird.config of static protocol?

Why filter export_default_route_from_bgp_to_ospf does not work for two
cases? 

Vladislav Grishin