OSPF config issue

[ullasmoopz]

Hi All,

       I am using a 2811 Router with NM-16ESW Swith Module in a branch, OSPF is the routing protocol Switch Module's Fa0/1 is used as Primary connection (with cost 1) and Router's Fa0/0 is used as backup connection (with cost 100).Do I need to configure Ospf in both Router's config mode as well as Switch's config mode ?

Pls help.

Appreciate anyone post the configurations.

[Peter Paluch]

Hi,

Do I need to configure Ospf in both Router's config mode as well as Switch's config mode ?

No. The NM-16ESW is a Layer2 switching module - it does not perform Layer3 switching (i.e. it does not have any routing capabilities). IP addresses will not be assigned to the individual physical ports of the module but rather to Switched Virtual interfaces (SVIs) - the interface Vlan X for each VLAN X you create. You will then configure the OSPF in a completely usual way in the global configuration mode of your router.

For example:

vlan database
 vlan 10
 vlan 20
exit
configure terminal
interface range Fa1/0/1 - 2
 switchport mode access
 switchport access vlan 10
interface range Fa1/0/3 - 4
 switchport mode access
 switchport access vlan 20
interface Vlan10
 ip address 192.168.10.1 255.255.255.0
interface Vlan20
 ip address 192.168.20.1 255.255.255.0
router ospf 1
 network 192.168.10.0 0.0.0.255 area 0
 network 192.168.20.0 0.0.0.255 area 0
 ... other networks ...
end

Best regards,

Peter

[ullasmoopz]

Hi Peter,

Do I need to configure Ospf in Router, my backup link is router's fa0/0 interface. ?

Switch Module's IOS I upgraded to ipservices, It supports Ospf.

Thanks

[Peter Paluch]

Hello,

I am afraid we do not understand each other. If we are talking about the NM-16ESW module then you could not have upgraded the switch module's IOS because it does not have any. You could have upgraded only the IOS image in the 2800 router into which the NM-16ESW is inserted.

Also, the NM-16ESW knows nothing about routing so you also cannot configure any OSPF on it.

Whether you need to run OSPF at all, and on what interfaces you need to run it, that depends on your network topology which is not currently clear to me - can you provide a simple drawing of your topology? Also, if your ISP does not run the OSPF towards your router then running OSPF is pointless.

Best regards,

Peter

[ullasmoopz]

Sorry Peter ,

the Module is not NM-16ESW , it is NME-16ES-1G.

Thanks

[Peter Paluch]

Hello,

That changes the situation considerably. But I still need to see the depiction of your network topology. This switching module behaves as a multi-layer switch and if it runs OSPF, you have basically two interconnected routers running in one 2800 chassis. The need to run OSPF has to be justified and that is why I need to know your network topology. Please include all used IP prefixes in the exhibit if possible.

Is the ISP running OSPF towards you?

Best regards,

Peter

[ullasmoopz]

Hi,

Pls check the Network diagram.

regards

[Peter Paluch]

Hello,

Thank you. Can you please answer also my question (now posted for the 3rd time in a row ) about the OSPF between you and the ISP?

Best regards,

Peter

[ullasmoopz]

Hi,

It is connected to OTN network ,This OTN network is configured with Ospf, I dont have the details of  ISP.

regards

[Peter Paluch]

Hello,

Thank you - actually, I was not asking about how your ISP runs its network, I just wanted to ascertain that you can establish OSPF adjacencies with your ISP. Otherwise it would not make much sense to run OSPF at all.

Okay, I assume that the module is recognized in your 2800 router as service-module GigabitEthernet2/0. One more question: is the module currently configured to switch between the Gi2/0 and Fa1/0, or is routing between them?

You have to understand the topology you have now. There is the switching module behaving as a multilayer switch, and your 2800 router. They are connected via their internal bus that behaves like a gigabit trunk between your router and the switch. Now the question is: does this trunk aggregate all VLANs defined on the multilayer switch and terminate them on the 2800 router, or are the VLANs already terminated at the switching module (under interface VLAN) and the trunk is used only as a routed link?

If you are not sure then please post the entire configuration of both your 2800 router and the switch module.

Best regards,

Peter

[ullasmoopz]

Hi Peter,

I am sending the Diagram and config of Router and Switch module, Actually I have 3 Connections to the ONT( Fa1/0/10, Fa1/0/11,Fa1/0/12) and Back up (Router's Fa0/1)to VSAT,I dont have much experience in routing.

Pls help

regards