Puzzling behaviour from bird ospf

[Harry Moyes]

Martin, List

I'm experimenting with a modest network of three linux based routers.
Each router has an 100bT Ethernet port, and a prism based wi-fi interface
using HostAP. All Ethernet ports connect to a common switch.
There is also a firewall box connected to the switch, not exchanging routes
with the network under test.
Running RIP bird distributes routes around this network very 
predictably. However I'm having problems with moving the
network over to OSPF. I'm uncertain if my problems are misconfiguration,
an external problem, or a bug in bird. I'm very much a beginner with OSPF so
it's entirely possible that I'm missing something obvious. 

Help would be very much appreciated.

If I start up bird on the routers, a normal OSPF election takes place
and routes are distributed as I expect. However if I leave the set up for
a few minutes the non local routes start to disappear from the routers.
Around the same time the non dr routers start complaining 

 22:54:08 <DBG> ShokaOSPF: Bad OSPF hello packet from 172.16.1.50 received: 
hello interval mismatch.

 I've tried a whole string of config file settings, but the following 
traces were  taken with the ospf settings defaulted as far as possible.
 
 The output from the three routers is reported below, with basic
 interface details and a copy of the config file used on all three routers.

My mailer seems to have wrapped the longer lines in the logs. If this
is inconvenient I can supply the same data as a plain text file.

A possibly related problem is that if I leave the routers running
overnight, birdc is unable to connect to bird on some of the boxes.

I've not been able to determine a pattern, but AFAICT the dr is never
showing this problem.
 
 Regards Harry Moyes



First Router output 
**************************************************************

[root at pei root]# /usr/local/sbin/bird
08-10-2003 22:42:02 <INFO> Guessed router ID 172.16.1.40 according to 
interface eth0
[root at pei root]# /usr/local/sbin/birdc
BIRD 1.0.6 ready.
bird> s o n
ShokaOSPF:
Router ID       Pri          State      DTime   Router IP       Interface
172.16.1.50       1         2way/other  00:37   172.16.1.50     eth0
172.16.1.20       1         2way/other  00:38   172.16.1.20     eth0
bird> s r
0.0.0.0/0          via 172.16.1.1 on eth0 [static1 22:42] (200)
127.0.0.0/8        dev lo [direct1 22:42] (240)
172.16.4.128/25    dev wlan0 [direct1 22:42] (240)
172.16.1.0/24      dev eth0 [direct1 22:42] (240)
bird> show ospf neighbors
ShokaOSPF:
Router ID       Pri          State      DTime   Router IP       Interface
172.16.1.50       1         full/dr     00:38   172.16.1.50     eth0
172.16.1.20       1         full/other  00:38   172.16.1.20     eth0
bird> show route
0.0.0.0/0          via 172.16.1.1 on eth0 [static1 22:42] (200)
127.0.0.0/8        dev lo [direct1 22:42] (240)
172.16.4.128/25    dev wlan0 [direct1 22:42] (240)
172.16.5.128/25    via 172.16.1.50 on eth0 [ShokaOSPF 22:43] I (150/20)
172.16.1.0/24      dev eth0 [direct1 22:42] (240)
                   via 172.16.1.50 on eth0 [ShokaOSPF 22:43] I (150/10)
172.16.2.128/25    via 172.16.1.20 on eth0 [ShokaOSPF 22:43] I (150/20)
bird> show route
0.0.0.0/0          via 172.16.1.1 on eth0 [static1 22:42] (200)
127.0.0.0/8        dev lo [direct1 22:42] (240)
172.16.4.128/25    dev wlan0 [direct1 22:42] (240)
172.16.1.0/24      dev eth0 [direct1 22:42] (240)
bird> show ospf neighbors
ShokaOSPF:
Router ID       Pri          State      DTime   Router IP       Interface
172.16.1.50       1         init/other  00:31   172.16.1.50     eth0
172.16.1.20       1         init/other  00:37   172.16.1.20     eth0
bird> show ospf neighbors
ShokaOSPF:
Router ID       Pri          State      DTime   Router IP       Interface
172.16.1.20       1         init/other  00:30   172.16.1.20     eth0
172.16.1.50       1         init/other  00:39   172.16.1.50     eth0
bird> show route
0.0.0.0/0          via 172.16.1.1 on eth0 [static1 22:42] (200)
127.0.0.0/8        dev lo [direct1 22:42] (240)
172.16.4.128/25    dev wlan0 [direct1 22:42] (240)
172.16.1.0/24      dev eth0 [direct1 22:42] (240)
bird> 08-10-2003 22:53:20 <DBG> ShokaOSPF: Bad OSPF hello packet from 
172.16.1.50 received: hello interval mismatch.
08-10-2003 22:53:41 <DBG> ShokaOSPF: Bad OSPF hello packet from 172.16.1.50