OSPF stub area bug

gnijs · ‎05-17-2011

Seems like the bug toolkit is not working in the office, so i'll try here.

It seems i am running against an OSPF bug. I have the following topology:

----- OSPF AREA 0 ----- ROUTER A ------- OSPF AREA 1 ---------- ROUTER B -------- OSPF AREA 1 ------ ROUTER C

AREA 1 is a totally stubby area and router A is injecting a default route in to AREA 1

I can see this default route on router B, however, i don't see this route on ROUTER C :-(

and the OSPF connection between router B & Router C is up and running.

For me , this is a bug, could someone confirm ?.

I am running this on C3750 platform with 12.2(25)SEE3. I know this is rather old, but it has worked flawlessly until now. We have

several systems running this config in production and they are not easy to upgrade. So i need real confirmation that this is indeed a problem

on this version, before we are going to ask for hard-to-get mainenance windows on our production systems.

Still waiting for the results from bug toolkit: "Bug Toolkit is processing your request. Please wait"...and wait ...and wait...and wait...

It seems the router gets the summary (see below), but he does not install it in its routing table.

Is this possible because he does not know the advertising router ? (10.96.56.1 = loopback of router A, but loopback is in area 0, so not advertised to area 1)

regards,

Geert.

Shots:

ROUTER B:

sh ip route

Gateway of last resort is 10.102.82.13 to network 0.0.0.0
O*IA 0.0.0.0/0 [110/2] via 10.102.82.13, 00:18:44, Vlan30

Summary Net Link States (Area 1.1.2.20)

Link ID ADV Router Age Seq# Checksum
0.0.0.0 10.96.56.1 714 0x80000A6C 0x00CF55

ROUTER C:

sh ip route

Gateway of last resort is not set

Summary Net Link States (Area 1.1.2.20)

Link ID ADV Router Age Seq# Checksum
0.0.0.0 10.96.56.1 778 0x80000A6C 0x00CF55

gnijs · ‎05-17-2011

ok, problem seems to be indeed router C does not know router A:

#sh ip ospf database router adv-router 10.96.56.1

OSPF Router with ID (10.102.82.2) (Process ID 1000)

Router Link States (Area 1.1.2.20)

Adv Router is not-reachable
LS age: 1741
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 10.96.56.1
Advertising Router: 10.96.56.1
LS Seq Number: 80000308
Checksum: 0x98A9
Length: 36
Area Border Router
Number of Links: 1

   Link connected to: a Transit Network
     (Link ID) Designated Router address: 10.102.82.14
     (Link Data) Router Interface address: 10.102.82.13
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

#sh ip route 10.96.56.1
% Subnet not in table

Why is this not a problem for router B ???

sh ip ospf database router adv-router 10.96.56.1

OSPF Router with ID (10.102.82.1) (Process ID 1000)

Router Link States (Area 1.1.2.20)

Routing Bit Set on this LSA
LS age: 710
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 10.96.56.1
Advertising Router: 10.96.56.1
LS Seq Number: 80000309
Checksum: 0x96AA
Length: 36
Area Border Router
Number of Links: 1

    Link connected to: a Transit Network
     (Link ID) Designated Router address: 10.102.82.14
     (Link Data) Router Interface address: 10.102.82.13
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

OSPF Router with ID (10.106.48.1) (Process ID 3000)
# sh ip route 10.96.56.1
% Subnet not in table

ha, found the problem: it seems router C does not know the link router A-B :-)

sh ip route 10.102.82.13
% Subnet not in table

gnijs · ‎05-17-2011

again, because the advertising router of this subnet is router A :-)

On router B:

#sh ip ospf database router 10.102.82.1

OSPF Router with ID (10.102.82.1) (Process ID 1000)

Router Link States (Area 1.1.2.20)

LS age: 1797
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 10.102.82.1
Advertising Router: 10.102.82.1
LS Seq Number: 8000030D
Checksum: 0x4557
Length: 72
Number of Links: 4

    Link connected to: a Stub Network
     (Link ID) Network/subnet number: 10.104.247.0
     (Link Data) Network Mask: 255.255.255.128
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

    Link connected to: a Stub Network
     (Link ID) Network/subnet number: 10.102.82.1
     (Link Data) Network Mask: 255.255.255.255
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

    Link connected to: a Transit Network
     (Link ID) Designated Router address: 10.102.82.252
     (Link Data) Router Interface address: 10.102.82.252
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

    Link connected to: a Transit Network
     (Link ID) Designated Router address: 10.102.82.14
     (Link Data) Router Interface address: 10.102.82.14
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

#sh ip ospf database network 10.102.82.14

OSPF Router with ID (10.102.82.1) (Process ID 1000)

Net Link States (Area 1.1.2.20)

Routing Bit Set on this LSA
LS age: 1395
Options: (No TOS-capability, DC)
LS Type: Network Links
Link State ID: 10.102.82.14 (address of Designated Router)
Advertising Router: 10.102.82.1
LS Seq Number: 80000318
Checksum: 0x67C5
Length: 32
Network Mask: /29
Attached Router: 10.102.82.1
Attached Router: 10.96.56.1

On router C , however, i don't have this LSA:

#sh ip ospf database router 10.102.82.1

OSPF Router with ID (10.102.82.2) (Process ID 1000)

Router Link States (Area 1.1.2.20)

LS age: 1697
Options: (No TOS-capability, DC)
LS Type: Router Links
Link State ID: 10.102.82.1
Advertising Router: 10.102.82.1
LS Seq Number: 8000030D
Checksum: 0x4557
Length: 72
Number of Links: 4

    Link connected to: a Stub Network
     (Link ID) Network/subnet number: 10.104.247.0
     (Link Data) Network Mask: 255.255.255.128
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

    Link connected to: a Stub Network
     (Link ID) Network/subnet number: 10.102.82.1
     (Link Data) Network Mask: 255.255.255.255
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

    Link connected to: a Transit Network
     (Link ID) Designated Router address: 10.102.82.252
     (Link Data) Router Interface address: 10.102.82.252
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

    Link connected to: a Transit Network
     (Link ID) Designated Router address: 10.102.82.14
     (Link Data) Router Interface address: 10.102.82.14
      Number of TOS metrics: 0
       TOS 0 Metrics: 1

#sh ip ospf database network 10.102.82.14

OSPF Router with ID (10.102.82.2) (Process ID 1000)

???? hum......

cadet alain · ‎05-17-2011

Hi Geert,

0.0.0.0 10.96.56.1 778 0x80000A6C 0x00CF55

10.96.56.1 is the router-id and it is not mandatory to be reachable, ain't it?

 Router Link States (Area 1.1.2.20)

What is this area number? it is not 0 nor 1.

Can you post output of these commands on each router:

-sh ip ospf int brief

-sh ip ospf nei

-sh ip protocols

-sh run | s ospf

-sh ip route os

-sh ip os database

-sh ip ospf

Regards.

Alain.

Don't forget to rate helpful posts.

esomarriba · ‎05-17-2011

Hi Geert Nijs,

Try debugging the ospf process:

— Command: debug ospf ism
— Command: debug ospf ism (status|events|timers)
— Command: no debug ospf ism
— Command: no debug ospf ism (status|events|timers)

— Command: debug ospf nsm
— Command: debug ospf nsm (status|events|timers)
— Command: no debug ospf nsm
— Command: no debug ospf nsm (status|events|timers)

— Command: debug ospf lsa
— Command: debug ospf lsa (generate|flooding|refresh)
— Command: no debug ospf lsa
— Command: no debug ospf lsa (generate|flooding|refresh)

— Command: debug ospf zebra
— Command: debug ospf zebra (interface|redistribute)
— Command: no debug ospf zebra
— Command: no debug ospf zebra (interface|redistribute)

— Command:show debugging ospf

To better assist you, do you have a network diagram?

HTH,

Elyinn.-