OSPF, missing external network prefix

[Eugene M. Zheganin]

Hi.

On 08.12.2015 18:23, Ondrej Zajicek wrote:
> On Tue, Dec 08, 2015 at 06:10:20PM +0500, Eugene M. Zheganin wrote:
>> I've also noticed that this prefix is missing from 'show ospf state'
>> output files, but present in 'show ospf state all' output files, but
>> along with a IP address of 172.16.5.159. This is an IP address of a
>> router this prefix is originating from (it's an address of it's tunnel
>> most close to the area 0), and it's not directly reachable from the
>> routers which FIB is missing it, so I suppose this may be the reason.
> Yes, that is expected behavior. Don't know why these routes are available
> on other Cisco routes.
They are (for example this output is from Cisco router and it's not in
area 0):

kosm114#sh ip route 192.168.114.192
Routing entry for 192.168.114.192/26
  Known via "ospf 10", distance 110, metric 20, type extern 2, forward
metric 22223
  Last update from 172.16.1.50 on Tunnel0, 4d00h ago
  Routing Descriptor Blocks:
  * 172.16.1.50, from 192.168.0.15, 4d00h ago, via Tunnel0
      Route metric is 20, traffic share count is 1

kosm114#sh ip ospf inter
kosm114#sh ip ospf interface
Tunnel1 is up, line protocol is up
  Internet Address 172.16.1.67/31, Area 19
  Process ID 10, Router ID 192.168.141.193, Network Type POINT_TO_POINT,
Cost: 15111
  Transmit Delay is 1 sec, State POINT_TO_POINT
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:07
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 2/2, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 8, maximum is 50
  Last flood scan time is 0 msec, maximum is 112 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 192.168.0.15
  Suppress hello for 0 neighbor(s)
Tunnel0 is up, line protocol is up
  Internet Address 172.16.1.51/31, Area 19
  Process ID 10, Router ID 192.168.141.193, Network Type POINT_TO_POINT,
Cost: 11111
  Transmit Delay is 1 sec, State POINT_TO_POINT
  Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
    oob-resync timeout 40
    Hello due in 00:00:05
  Supports Link-local Signaling (LLS)
  Cisco NSF helper support enabled
  IETF NSF helper support enabled
  Index 1/1, flood queue length 0
  Next 0x0(0)/0x0(0)
  Last flood scan length is 3, maximum is 50
  Last flood scan time is 0 msec, maximum is 104 msec
  Neighbor Count is 1, Adjacent neighbor count is 1
    Adjacent with neighbor 192.168.0.15
  Suppress hello for 0 neighbor(s)
> Not sure if 172.16.5.159 should or should not be propagated, perhaps it
> is just missing. If you have BIRD on originating router, you could
> remove explicit next hop by setting 'gw = 0.0.0.0;' in the OSPF export
> filter (on the originating router).
>
Unfortunately, these NSSA prefixes are originating from Cisco devices.
Is there some workaround to make these prefixes available in other
areas, except of reverting NSSA areas to ordinary ones ? After all the
external routes from NSSAs should be visible in other areas, since they
are converted from type 7 to type 7 by the ABR, right ?

Thanks.
Eugene.