ospf

[highland8]

Hello

I have routerA connected (fa0) to routerB(fa0) which is connected (fa1) to routerC(fa0) which is connected(fa1) to routerD(fa0). Each router has two networks connected to serial0 and serial1. Each router has ospf launched on all interfaces.

As i understeand all routers should have routes to all networks in it's routing tables. I noticed that each router has routes to networks which are connected to neighbouring router: for example routerB has routes to networks connected to routerA and routerC but does not have routes to networks connected to routerD. RouterA has only routes to networks which are connected to routerB, and does not have routes to networks connected to routerC and routerD.
Of course each router has it's own routes (to networks directly connected).

Why is it so ? I noticed that SOMETIMES i see routes to networks which are connected to neighbour of my neighbour (but only sometimes).

I'm using Boson 6beta3 simulator....

Thanx for any clue.
Michal

 

[jneiberger]

Can you post your configs so we can take a look at thrm?

 

[highland8]

OK, my real confuguration is:
Router Redge connected to Rmain connected to Rremote.
Rremote is connected to newtwork 223.0.0.128/28 but this route is not seen by Redge.

Redge configuration:
interface Serial0<connection to ISP>
ip address 200.200.100.2 255.255.255.252
no ip directed-broadcast
clock rate 125000
backup interface
!
interface Serial1<connection to Rmain>
ip address 223.0.0.165 255.255.255.252
no ip directed-broadcast
backup interface
!
interface Ethernet0 <connection to local network>
ip address 223.0.0.161 255.255.255.252
no ip directed-broadcast
bandwidth 10000
backup interface
no fair-queue
ip ospf cost 100
!
!
router ospf 1
network 200.200.100.0 0.0.0.3 area 100
network 223.0.0.160 0.0.0.3 area 100
network 223.0.0.164 0.0.0.3 area 100

Rmain configuration:
interface Serial0 <connection to Redge>
ip address 223.0.0.166 255.255.255.252
no ip directed-broadcast
clock rate 125000
backup interface
!
interface Serial1 <connection to Rremote>
ip address 223.0.0.169 255.255.255.252
no ip directed-broadcast
backup interface
!
interface FastEthernet0/0
no ip address
no ip directed-broadcast
backup interface
no fair-queue
!<some local networks>
interface FastEthernet0/0.1
encapsulation dot1q 10
ip address 223.0.0.1 255.255.255.192
!
interface FastEthernet0/0.2
encapsulation dot1q 20
ip address 223.0.0.65 255.255.255.224
!
interface FastEthernet0/0.3
encapsulation dot1q 30
ip address 223.0.0.145 255.255.255.240
!
!
router ospf 1
network 223.0.0.164 0.0.0.3 area 100
network 223.0.0.168 0.0.0.3 area 100
network 223.0.0.0 0.0.0.63 area 100
network 223.0.0.64 0.0.0.31 area 100
network 223.0.0.128 0.0.0.15 area 100
network 223.0.0.144 0.0.0.15 area 100

Rremote configuration:
interface Serial0 <connection to Rmain>
ip address 223.0.0.170 255.255.255.252
no ip directed-broadcast
clock rate 125000
backup interface
!
interface Ethernet0 <local network>
ip address 223.0.0.129 255.255.255.240
no ip directed-broadcast
bandwidth 10000
backup interface
no fair-queue
ip ospf cost 100

The problem is that on Redge my routing table is:
S* 0.0.0.0 [1/0] via 200.200.100.1
200.200.100.0/30 is subnetted, 1 subnets
C 200.200.100.0 is directly connected, Serial0
223.0.0.0/24 is variably subnetted, 7 subnets
C 223.0.0.160/30 is directly connected, Ethernet0
O 223.0.0.168/30 [110/64] via 223.0.0.169, 00:06:22, Serial1
O 223.0.0.0/26 [110/64] via 223.0.0.1, 00:06:22, Serial1
O 223.0.0.64/27 [110/64] via 223.0.0.65, 00:06:22, Serial1
O 223.0.0.144/28 [110/64] via 223.0.0.145, 00:06:22, Serial1
O 223.0.0.96/27 [110/100] via 223.0.0.97, 00:06:22, Ethernet0
C 223.0.0.164/30 is directly connected, Serial1
but there is no route to network 223.0.0.128/28 (which is connected to Rremote), while on Rmain there is such route:
S* 0.0.0.0 [1/0] via 223.0.0.165
223.0.0.0/24 is variably subnetted, 8 subnets
C 223.0.0.164/30 is directly connected, Serial0
C 223.0.0.0/26 is directly connected, 223.0.0.1
C 223.0.0.64/27 is directly connected, 223.0.0.65
C 223.0.0.144/28 is directly connected, 223.0.0.145
O 223.0.0.160/30 [110/64] via 223.0.0.165, 00:08:34, Serial0
O 223.0.0.128/28 [110/64] via 223.0.0.129, 00:08:34, Serial1
O 223.0.0.96/27 [110/228] via 223.0.0.165, 00:08:30, Serial0
C 223.0.0.168/30 is directly connected, Serial1
200.200.100.0/30 is subnetted, 1 subnets
O 200.200.100.0 [110/64] via 223.0.0.165, 00:08:34, Serial0

why information about route 223.0.0.128/28 is not propagating from Rmain to Redge ?

I also tried to do ospf on all routers on 0.0.0.0 255.255.255.255 but did not helped. I used Boson 6b3 simulator.

Thanx
Michal

 

[jneiberger]

You neglected to include the OSPF configuration for Rremote. Regardless, on Rmain you have the following line:

network 223.0.0.128 0.0.0.15 area 100

That statement belongs in the OSPF config on Rremote since that is where that network lives. Remove that line from Rmain and add it to Rremote, and let's see if that makes your network a bit happier.

 

[jneiberger]

Oh, I forgot. I want to strongly reiterate the advice I gave you in your other post a day or so ago. It's a *very* good idea to use 0.0.0.0 wildcard masks in our OSPF network statements.

So, for example, in Rremote you would have the following:

network 223.0.0.129 0.0.0.0 area 100

instead of this:

network 223.0.0.128 0.0.0.15 area 100

Note that the last octet changed to exactly match the IP address on the interface. This is much easier to troubleshoot, not to mention being more clear about what's actually happening. All-zero wildcard masks in your OSPF statements would be a good habit to get into.

 

[highland8]

OK, i removed network 223.0.0.128 0.0.0.15 area 100 from Rmain, here is my ospf config on Rremote:

router ospf 1
network 223.0.0.168 0.0.0.3 area 100
network 223.0.0.128 0.0.0.15 area 100

But still the problem exists.
Morover it was only example. I have more routers connected and the problem is similar -> they forgot routes to networks which are two hops from them (but not always).

May it be boson bug ?

Thanx
MIchal

 

[jneiberger]

It certainly could be a bug. I would never expect a router simulator to behave correctly, but that's just my bias.

 

[leedsit]

Hi,

Im using the same version of Boson, and yup it is a bug, I get the same issues. Best wait till it comes of Beta, but then I still wont hold my breath.

Lee

LEEroy
MCNE6,CCNA2,CWNA, Project+

 

[jneiberger]

If you can afford it, buy some 2500-series routers off of ebay. If you need routers then get routers, not router simulators. There just is no substitute for the real thing if you have the resources to buy them. 2500s are cheap so you should be able to pickup three or four of them without much expense.