OSPF routes not in routing table

Hi all,

I'm still mostly a n00b when it comes to OSPF, but I've been using it
in a fairly basic fashion for a number of years. I'm really stuck on
this one, since I have a similar config going on another router and
it's working as I'd expect it to.

Hardware/Software Details: 1721 w/12.3(11)T5 IP BASE software, one T1
WIC, one ADSL WIC

Goal: both the T1 and ADSL lines come back to the same 7206. The T1 is
frame converted to ATM at the dslam and long story short, that
conversion doesn't let me see if the T1 is up or down from the 7206
side, so I'm running OSPF. ADSL is a backup line. I want OSPF to
advertise the LAN block on the 1721 back to the 7206 and the 7206 to
advertise default to the 1721.

Problem: Both routers are in area 0, and both see each other as
neighbors. The 7206 has the 1721s loopback, serial ints and LAN ints
in it's OSPF db and routing table. The 1721 has routes (including
default) in the ospf db, but not in the routing table.

Brief config snippets from both:

7206:
router ospf 1
router-id 10.10.111.1
log-adjacency-changes
area 0 authentication message-digest
passive-interface default
no passive-interface ATM2/0.10246 <- ADSL
no passive-interface ATM2/0.10248 <- T1
no passive-interface ATM4/0.12655
no passive-interface FastEthernet5/0.1
network 10.10.104.0 0.0.0.255 area 0 <-T1 interface
network 10.10.110.0 0.0.0.255 area 0 <-ADSL interface
network 10.10.111.1 0.0.0.0 area 0
network 10.10.111.8 0.0.0.7 area 0
network 10.10.111.24 0.0.0.7 area 0
default-information originate always
!

1721:
router ospf 1
router-id 10.10.111.254
log-adjacency-changes
redistribute connected subnets
passive-interface default
no passive-interface ATM0.1
no passive-interface Serial0.1
network 10.10.104.248 0.0.0.0 area 0 <-T1 interface
network 10.10.108.16 0.0.0.15 area 0 <-LAN
network 10.10.110.10 0.0.0.0 area 0 <-ADSL interface
!

So no problems on the 7206 side, I see all the routes I need to see.
On the 1721 though:

Gateway of last resort is 0.0.0.0 to network 0.0.0.0

C 10.10.104.0/24 is directly connected, Serial0.1
10.10.111.0/32 is subnetted, 1 subnets
C 10.10.111.254 is directly connected, Loopback0
C 10.10.110.0/24 is directly connected, ATM0.1
10.10.108.0/28 is subnetted, 1 subnets
C 10.10.108.16 is directly connected, FastEthernet0
S* 0.0.0.0/0 is directly connected, Serial0.1

And if I drop that static default route, no ospf default route jumps in
to take it's place.

Here's the 1721 ospf database, you can see it's receiving a default:

Infinia#sh ip ospf database

OSPF Router with ID (10.10.111.254) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link
count
10.10.111.1 10.10.111.1 50 0x800016A8 0x001E53 9
10.10.111.3 10.10.111.3 1461 0x800030B0 0x00F546 18
10.10.111.254 10.10.111.254 629 0x80000012 0x00BB60 5

Type-5 AS External Link States

Link ID ADV Router Age Seq# Checksum Tag
0.0.0.0 10.10.111.1 312 0x8000CC1B 0x00089D 1
10.10.111.254 10.10.111.254 629 0x80000002 0x003C1B 0
Infinia#

So what am I missing here? I have a few other sites with similar
configs and I have no problem getting a default route. In fact, other
than the IOS version on those, there's really no difference. Is this a
bug, or am I just not getting something fundamental here?

Thanks,

Charles

 

OSPF message authentication is configured on 7206 but is not configured
on 1721.


For the OSPF process, "network 10.0.0.0 0.255.255.255 area 0" would
suffice.


Why is redistribute connected subnets command being used on 1721?

 

I must have missed it in the cut and paste - the routers are both using
md5 keys, and the session is up.

I am most interested in getting the LAN route back to the 7206.

Thanks,

Charles

 

Post the 1721's OSPF database and routing table after the OSPF
authentication issue has been addressed.

Post the output of "show ip ospf database router" from the 1721.

 

The "redistribute connected subnets" command maybe causing an issue
with the forwarding address as it is installing an external in the
1721's OSPF database

For testing purpose, pull that command.

 

OK, the authentication line was in there. I removed "redistribute
connected subnets" as well, and then for good measure went ahead and
cleared the ospf routing process. Still no default showing up (or any
other routes via ospf).

Here's the output of "sh ip ospf database router", it's pretty long...

I also noticed this little weirdness in the first few entries that
struck me as odd:

"(Link Data) Router Interface address: 0.0.6.214"

Thanks again for all your help...

Charles


Infinia#sh ip ospf database router

OSPF Router with ID (10.10.111.254) (Process ID 1)

Router Link States (Area 0)

Adv Router is not-reachable
LS age: 536
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 10.10.111.1
Advertising Router: 10.10.111.1
LS Seq Number: 800016C7
Checksum: 0xDF72
Length: 132
AS Boundary Router
Number of Links: 9

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.110.1
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metrics: 1
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 10.10.111.254
(Link Data) Router Interface address: 0.0.6.214
Number of TOS metrics: 0
TOS 0 Metrics: 2

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.104.1
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 10.10.111.254
(Link Data) Router Interface address: 0.0.6.215
Number of TOS metrics: 0
TOS 0 Metrics: 33

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 10.10.111.3
(Link Data) Router Interface address: 10.10.111.25
Number of TOS metrics: 0
TOS 0 Metrics: 65
Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.111.24
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 65

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 10.10.111.3
(Link Data) Router Interface address: 10.10.111.13
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.111.12
(Link Data) Network Mask: 255.255.255.252
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.111.1
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metrics: 1

Adv Router is not-reachable
LS age: 150
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 10.10.111.3
Advertising Router: 10.10.111.3
LS Seq Number: 800030D0
Checksum: 0xB566
Length: 240
AS Boundary Router
Number of Links: 18

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.112.0
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.208
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 10.10.111.1
(Link Data) Router Interface address: 10.10.111.26
Number of TOS metrics: 0
TOS 0 Metrics: 65

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.111.24
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 65

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.232
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.240
(Link Data) Network Mask: 255.255.255.240
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.118.128
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.111.16
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 10.10.111.1
(Link Data) Router Interface address: 10.10.111.14
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.111.12
(Link Data) Network Mask: 255.255.255.252
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.111.3
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.80
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.228
(Link Data) Network Mask: 255.255.255.252
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.204
(Link Data) Network Mask: 255.255.255.252
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.224
(Link Data) Network Mask: 255.255.255.252
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.72
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 1

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.64
(Link Data) Network Mask: 255.255.255.248
Number of TOS metrics: 0
TOS 0 Metrics: 1
Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.107.0
(Link Data) Network Mask: 255.255.255.192
Number of TOS metrics: 0
TOS 0 Metrics: 1


LS age: 1053
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 10.10.111.254
Advertising Router: 10.10.111.254
LS Seq Number: 80000031
Checksum: 0x7D7F
Length: 84
AS Boundary Router
Number of Links: 5

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.108.16
(Link Data) Network Mask: 255.255.255.240
Number of TOS metrics: 0
TOS 0 Metrics: 1
Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 10.10.111.1
(Link Data) Router Interface address: 10.10.110.10
Number of TOS metrics: 0
TOS 0 Metrics: 130

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.110.0
(Link Data) Network Mask: 255.255.255.0
Number of TOS metrics: 0
TOS 0 Metrics: 130

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 10.10.111.1
(Link Data) Router Interface address: 10.10.104.248
Number of TOS metrics: 0
TOS 0 Metrics: 65

Link connected to: a Stub Network
(Link ID) Network/subnet number: 10.10.104.0
(Link Data) Network Mask: 255.255.255.0
Number of TOS metrics: 0
TOS 0 Metrics: 65

Infinia#

 

It looks like the LSA's are not be installed in the 1721's routing
table because the LSA are flagged "Adv Router is not-reachable". There
are several causes of this and you need to work thru to find out which
one is occuring in your case.

see Cisco doc "Why Are Some OSPF Routes in the Database but Not in the
Routing Table?"
http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009481a.shtml


Please post the complete configue for the 1721 and the 7206 interface
config connected to the 1721.

Also post the config and the interface config for a comparable site
that is working along with IOS version on the remote site along with
"sh ip ospf database router" for the working site.

 

Check that the IP addressing for the T1 and the ADSL link on the 1721
are not reversed.

 

Post the output of "show ip ospf interface" for both the T1 and the
ADSL link on the 7206 and the 1721 routers

 

any joy ?

 

Working on it.

Thanks for the public one-on-one troubleshooting...

I think I can probably fix this by altering the config to use a
dedicated /30 on each link. Right now both links are atm subifs on the
7206 and each interface uses an "ip unnumbered loopback X", which seems
like it may be causing the "adv router not reachable" issue. This
looks like it's addressed in that CCO doc you linked - I need to parse
that more carefully. I'm going to try futzing and then post back. But
in the meantime I'll put everything you asked for in here for the
archives.

sample non-working config (note that my cvs config puller removes the
md5 keys):

7206-

interface ATM2/0.10246 point-to-point
ip unnumbered Loopback7
ip ospf authentication message-digest
! ip ospf message-digest-key 1 md5 <removed>
ip ospf mtu-ignore
pvc 0/10246
encapsulation aal5snap
!
interface Loopback7
description loopback for 10.10.110.0/24 sdsl
ip address 10.10.110.1 255.255.255.255
!
ip route 10.10.110.10 255.255.255.255 ATM2/0.10246

1721-

interface ATM0.1 point-to-point
ip address 10.10.110.10 255.255.255.0
ip ospf authentication message-digest
! ip ospf message-digest-key 1 md5 7 <removed>
ip ospf network point-to-point
ip ospf mtu-ignore
pvc 0/35
encapsulation aal5snap
!

And now an example of a working config which uses numbered interfaces.
Note that since there's no SDSL WIC that works with Nokia dslams this
is bridged:

7206-

interface ATM4/0.12655 point-to-point
bandwidth 1536
ip address 10.10.111.25 255.255.255.248 (using a /29 so I have an IP
for bridge mgmt)
ip ospf authentication message-digest
! ip ospf message-digest-key 1 md5 <removed>
ip ospf mtu-ignore
atm route-bridged ip
pvc 0/12655
abr 1536 1536
encapsulation aal5snap
!

3640-

interface FastEthernet0/0.3
description vlan 3 - sdsl to level3 circid -
bandwidth 1536
encapsulation dot1Q 3
ip address 10.10.111.26 255.255.255.248
no ip proxy-arp
ip ospf authentication message-digest
! ip ospf message-digest-key 1 md5 <removed>
ip ospf network point-to-point
ip ospf mtu-ignore


Next up, requested ospf db from the working site:

router-568#sh ip ospf database

OSPF Router with ID (10.10.111.3) (Process ID 1)

Router Link States (Area 0)

Link ID ADV Router Age Seq# Checksum Link
count
10.10.111.1 10.10.111.1 80 0x80001721 0x002ACD 9
10.10.111.3 10.10.111.3 985 0x80003129 0x0002C0 18
10.10.111.254 10.10.111.254 39 0x8000008B 0x00C8D9 5

Type-5 AS External Link States

Link ID ADV Router Age Seq# Checksum Tag
0.0.0.0 10.10.111.1 80 0x8000CC94 0x001517 1
router-568#sh ip route ospf
10.10.104.0/24 is variably subnetted, 2 subnets, 2 masks
O 10.10.104.0/24 [110/68] via 10.10.111.13, 2d19h,
FastEthernet0/0.2
O 10.10.104.1/32 [110/2] via 10.10.111.13, 2d19h,
FastEthernet0/0.2
10.10.111.0/24 is variably subnetted, 5 subnets, 3 masks
O 10.10.111.1/32 [110/2] via 10.10.111.13, 2d19h,
FastEthernet0/0.2
10.10.110.0/24 is variably subnetted, 2 subnets, 2 masks
O 10.10.110.0/24

(FE 0/0.2 is a 10Mb metro ether line, FE 0/0.3 is a 1.5Mb SDSL line
terminated on a bridge)

As to the post regarding numbering, it is correct.

Lastly, the interface info for both the 7206 and 1721 (note that the
network types match):

7206-

router-l3t#sh ip ospf interface atm 2/0.10246
ATM2/0.10246 is up, line protocol is up
Internet Address 0.0.0.0/0, Area 0
Process ID 1, Router ID 10.10.111.1, Network Type POINT_TO_POINT,
Cost: 2
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
Hello due in 00:00:04
Index 306/306, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 2, maximum is 2
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.10.111.254
Suppress hello for 0 neighbor(s)
Message digest authentication enabled
Youngest key id is 1

1721-

Infinia#sh ip ospf interface serial 0.1
Serial0.1 is up, line protocol is up
Internet Address 10.10.104.248/24, Area 0
Process ID 1, Router ID 10.10.111.254, Network Type POINT_TO_POINT,
Cost: 65 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 00:00:04
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 4 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 10.10.111.1
Suppress hello for 0 neighbor(s)
Message digest authentication enabled
Youngest key id is 1

I think that's all the info... I need to investigate this unnumbered
issue, I think that will take me somewhere.

Thanks for all your help!

Charles

 

Yes!

http://www.cisco.com/en/US/tech/tk365/technologies_tech_note09186a008009481a.shtml#r4

It was the numbered+unnumbered issue linked above. Should have posted
my interface configs right off the bat, sorry about that. I'm so used
to the unnumbered stuff since 99.999% of our lines are setup that
way... habit.

Infinia#sh ip route ospf | inc 0.0.0.0
O*E2 0.0.0.0/0 [110/1] via 10.10.111.221, 00:01:54, Serial0.1

Now I just have to clean things up and I think this is all good to go.

One more question, for a site like this where it's just two lines with
one backing the other up, should I just look at setting up another
area? This is a pretty rare config for us, so I'm tempted to leave it
as-is, and I've never played with stub areas or NSSA's... Any opinions
on that?

Thanks again for all the help Merv,

Charles

 

For one site I would not worry about setting up another area.

I would encourage you to simpify you network statments to one.