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RE: Disappearing route posted 11/26/2003
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John,
Look at R5's routing table and you should be able to quickly see the
problem. 

R5:
O IA    150.50.1.0/24 [110/192] via 12.1.1.2, 00:32:50, Serial0
^^^^
If the virtual link was working between R2 and R5, R5 would not see area 0
routes as inter-area since R5 would also be an area 0 router. With a working
virtual link between them, R5 would see area 0 routes as intra-area. The
150.50.1.0/24 area 0 route from R2 should show up as intra-area on R5 if the
virtual link was working:

O       150.50.1.0/24 [110/192] via 12.1.1.2, 00:32:50, Serial0
^

As a side note, although that is a good link that Bob sent, it is missing a
couple other reasons why a 'route' may be in the database but not in the
routing table. This is one of them ;-)

Brian Dennis, CCIE #2210 (R&S/ISP-Dial/Security)
bdennis@xxxxxxxxxxxxxxxxxxxxxx 
Toll Free: 877-224-8987
Direct: 775-745-6404 (Outside the US and Canada)
Internetwork Expert, Inc.
http://www.InternetworkExpert.com

-----Original Message-----
From: nobody@xxxxxxxxxxxxxx [mailto:nobody@xxxxxxxxxxxxxx] On Behalf Of Bob
Sinclair
Sent: Wednesday, November 26, 2003 2:45 PM
To: John Underhill; ccielab Groupstudy
Subject: Re: Disappearing route

John,

Not sure of your problem, but, if you have not seen it, here is a great
article that directly addresses your question.  It is titled:  "Why are some
OSPF Routes in the Database but not in the Routing Table?

http://www.cisco.com/en/US/tech/tk365/tk480/technologies_tech_note09186a0080
09481a.shtml

HTH,

-Bob Sinclair
 CCIE #10427, CISSP, MCSE
 bsinclair@xxxxxxxxxxxxxxxxxx
----- Original Message ----- 
From: "John Underhill" <stepnwlf@xxxxxxxx>
To: "ccielab Groupstudy" <ccielab@xxxxxxxxxxxxxx>
Sent: Wednesday, November 26, 2003 5:30 PM
Subject: Disappearing route


>                P2M --R4
>                  /
>     area 0  /     VL  area 1        area 2
>       R1--R2 ---- P2M -R5 --- P2P --R7
>                \
>                  \
>                P2P--R6
>
> I have this config that I can't seem to make sense of.. Area 0 is on hdlc
> between r1 and r2. Area 1 is between a point to multipoint link on R2 to
the
> ser0 of r4 and r5. A p2p connection between r6 and r2. There is a virtual
link
> using r2 to r5 as the transit area. The serial1 is connected via ppp to
the s0
> of r7 in area 2. I am not using any authentication. Now here's the strange
> part. R7 sees all the routes, can ping all of them but the multipoint int
on
> r2, (coming up as a host route with p2m). R2 does not see routes injected
via
> R7 at all, but, they are showing up in the ospf database, just not in the
> route table. All other routers have full connectivity. R7 can ping r5, and
all
> other interfaces, including those that have to pass through the hub to
reach
> the end spokes. R2 in turn can ping everything up to r5. A trace shows r7
gets
> to r5 then the route is blackholed. Debugs show only a normal adjacency
> forming between routers involved. I think it might have something to do
with
> the VL. or a route summary. not sure, but one thing I wonder is how a
route
> can show up in the ospf database and not be installed in the route table..
> here's my configs..
>
> R2
> O    205.1.1.0/24 [110/65] via 12.1.1.5, 00:31:22, Serial0.1
> O    206.1.1.0/24 [110/65] via 13.1.1.2, 00:31:22, Serial0.2
>      172.18.0.0/18 is subnetted, 4 subnets
> O       172.18.128.0 [110/65] via 12.1.1.5, 00:31:22, Serial0.1
> O       172.18.192.0 [110/65] via 12.1.1.5, 00:31:22, Serial0.1
> O       172.18.0.0 [110/65] via 12.1.1.5, 00:31:22, Serial0.1
> O       172.18.64.0 [110/65] via 12.1.1.5, 00:31:22, Serial0.1
> C    202.1.1.0/24 is directly connected, Loopback0
>      12.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
> O       12.1.1.4/32 [110/64] via 12.1.1.4, 00:31:22, Serial0.1
> O       12.1.1.5/32 [110/64] via 12.1.1.5, 00:31:22, Serial0.1
> C       12.1.1.0/24 is directly connected, Serial0.1
>      13.0.0.0/30 is subnetted, 1 subnets
> C       13.1.1.0 is directly connected, Serial0.2
>      150.50.0.0/16 is variably subnetted, 4 subnets, 2 masks
> C       150.50.1.0/24 is directly connected, Serial1
> C       150.50.9.0/24 is directly connected, Dialer0
> C       150.50.9.2/32 is directly connected, Dialer0
> C       150.50.17.0/24 is directly connected, Ethernet0
>
> interface Loopback0
>  ip address 202.1.1.1 255.255.255.0
> interface Serial0.1 multipoint
>  ip address 12.1.1.2 255.255.255.0
>  ip ospf network point-to-multipoint
>  frame-relay map ip 12.1.1.4 101 broadcast
>  frame-relay map ip 12.1.1.5 102 broadcast
> !
> interface Serial0.2 point-to-point
>  ip address 13.1.1.1 255.255.255.252
>  frame-relay interface-dlci 103
> router ospf 100
>  router-id 202.1.1.1
>  log-adjacency-changes
>  area 1 virtual-link 205.1.1.1
>  passive-interface default
>  no passive-interface Serial0.1
>  no passive-interface Serial0.2
>  no passive-interface Serial1
>  network 12.1.1.0 0.0.0.255 area 1
>  network 13.1.1.0 0.0.0.3 area 1
>  network 150.50.1.0 0.0.0.255 area 0
> r5
>
> C    205.1.1.0/24 is directly connected, Loopback0
> O    207.1.1.0/24 [110/65] via 150.50.18.7, 00:32:48, Serial1
> O    206.1.1.0/24 [110/129] via 12.1.1.2, 00:32:48, Serial0
>      172.16.0.0/24 is subnetted, 1 subnets
> C       172.16.1.0 is directly connected, TokenRing0
>      172.18.0.0/16 is variably subnetted, 5 subnets, 2 masks
> C       172.18.128.0/18 is directly connected, Loopback3
> C       172.18.192.0/18 is directly connected, Loopback4
> S       172.18.0.0/16 is directly connected, Null0
> C       172.18.0.0/18 is directly connected, Loopback1
> C       172.18.64.0/18 is directly connected, Loopback2
>      12.0.0.0/8 is variably subnetted, 3 subnets, 2 masks
> O       12.1.1.4/32 [110/64] via 12.1.1.4, 00:32:48, Serial0
> C       12.1.1.0/24 is directly connected, Serial0
> O       12.1.1.2/32 [110/64] via 12.1.1.2, 00:32:50, Serial0
>      13.0.0.0/30 is subnetted, 1 subnets
> O       13.1.1.0 [110/128] via 12.1.1.2, 00:32:50, Serial0
>      150.50.0.0/16 is variably subnetted, 5 subnets, 2 masks
> O IA    150.50.1.0/24 [110/192] via 12.1.1.2, 00:32:50, Serial0
> C       150.50.9.1/32 is directly connected, Dialer0
> C       150.50.9.0/24 is directly connected, Dialer0
> C       150.50.18.7/32 is directly connected, Serial1
> C       150.50.18.0/24 is directly connected, Serial1
>
> interface Loopback0
>  ip address 205.1.1.1 255.255.255.0
>  ip ospf network point-to-point
> !
> interface Loopback1
>  ip address 172.18.0.1 255.255.192.0
>  ip ospf network point-to-point
> !
> interface Loopback2
>  ip address 172.18.64.1 255.255.192.0
>  ip ospf network point-to-point
> !
> interface Loopback3
>  ip address 172.18.128.1 255.255.192.0
>  ip ospf network point-to-point
> !
> interface Loopback4
>  ip address 172.18.224.1 255.255.192.0
>  ip ospf network point-to-point
>
> interface Serial0
>  ip address 12.1.1.5 255.255.255.0
>  encapsulation frame-relay
>  ip ospf network point-to-multipoint
>  no fair-queue
>  frame-relay map ip 12.1.1.2 301 broadcast
>
> router ospf 100
>  log-adjacency-changes
>  area 1 range 172.18.0.0 255.255.0.0
>  area 1 virtual-link 202.1.1.1
>  passive-interface default
>  no passive-interface Loopback0
>  no passive-interface Serial0
>  no passive-interface Serial1
>  network 12.1.1.0 0.0.0.255 area 1
>  network 150.50.18.0 0.0.0.255 area 2
>  network 172.18.0.0 0.0.63.255 area 1
>  network 172.18.64.0 0.0.63.255 area 1
>  network 172.18.128.0 0.0.63.255 area 1
>  network 172.18.192.0 0.0.63.255 area 1
>  network 205.1.1.0 0.0.0.255 area 1
> !
> ip classless
> ip route 172.18.0.0 255.255.0.0 Null0
> ip http server
>
> r7
>
> O IA 205.1.1.0/24 [110/65] via 150.50.18.5, 00:33:33, Serial0
> C    207.1.1.0/24 is directly connected, Loopback0
> O IA 206.1.1.0/24 [110/193] via 150.50.18.5, 00:33:33, Serial0
> O IA 172.18.0.0/16 [110/65] via 150.50.18.5, 00:33:33, Serial0
>      12.0.0.0/32 is subnetted, 3 subnets
> O IA    12.1.1.4 [110/128] via 150.50.18.5, 00:33:33, Serial0
> O IA    12.1.1.5 [110/64] via 150.50.18.5, 00:33:33, Serial0
> O IA    12.1.1.2 [110/128] via 150.50.18.5, 00:33:34, Serial0
>      13.0.0.0/30 is subnetted, 1 subnets
> O IA    13.1.1.0 [110/192] via 150.50.18.5, 00:33:34, Serial0
>      150.50.0.0/16 is variably subnetted, 4 subnets, 2 masks
> C       150.50.5.0/24 is directly connected, Serial1
> C       150.50.18.5/32 is directly connected, Serial0
> C       150.50.17.0/24 is directly connected, Ethernet0
> C       150.50.18.0/24 is directly connected, Serial0
>
> interface Loopback0
>  ip address 207.1.1.1 255.255.255.0
>  no ip directed-broadcast
>  ip ospf network point-to-point
>
> interface Serial0
>  ip address 150.50.18.7 255.255.255.0
>  no ip directed-broadcast
>  encapsulation ppp
>  no fair-queue
> !
> interface Serial1
>  ip address 150.50.5.68 255.255.255.0
>  no ip directed-broadcast
> !
> interface Async1
>  no ip address
>  no ip directed-broadcast
>  shutdown
> !
> router ospf 100
>  passive-interface default
>  no passive-interface Loopback0
>  no passive-interface Serial0
>  network 150.50.18.0 0.0.0.255 area 2
>  network 207.1.1.0 0.0.0.255 area 2
>
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