[j-nsp] SNMP polling a logical-system without encoding it asLS/RI at community

[Zenon Mousmoulas]

On 15 Ιαν 2009, at 5:25 ΜΜ, Zenon Mousmoulas wrote:

>
> On 15 Ιαν 2009, at 1:44 ΜΜ, Subodh Kumar wrote:
>
>> It would depend on which interface is your packet entering the system
>> (router).  Consider an example:
>>
>>           ________                    _________
>>          |       |                    |       |
>>          |       |      (lr1/ri2)     |       |
>>          |   R1  |--------------------| nms1  |
>>          |       |fe-0/0/3        em1 |       |
>>          |_______|                    |_______|
>>
>>
>>  - (lr1/ri2) indicate the routing-instance
>>  - Ip Address:
>>       nms1 (em1): 14.14.14.1
>>
>>
>> logical-systems lr1 {
>>  routing-instances {
>>     ri2 {
>>            ...
>>            interface fe-0/0/3;
>>            ...
>>     }
>>  }
>>  interfaces{
>>     fe-0/0/3 {
>>          unit 0 {
>>            family inet {
>>               address 14.14.14.2/24;
>>            }
>>        }
>>     }
>>     lo0 {
>>       unit 1 {
>>          family inet {
>>              address 14.14.14.100/32
>>          }
>>       }
>>     }
>>  }
>> }
>>
>>
>> Now if you send a SNMP packet from 'nms1' on ip-addess 14.14.14.100  
>> or
>> 14.14.14.2, that makes sure that packet is entering the system from
>> inetrafce fe-0/0/3 which is part of logical-systems 'lr1'. In this  
>> case
>> you don't need to specify the prefix 'lr1/default' in the community
>> string.
>>
>> In your case, it looks that the SNMP packet is getting into the  
>> router
>> through 'fxp0' or some interface that is part of 'default'
>> routing-instance. Does the 'ping 10.0.0.5' from the NMS work for you?
>
>
> Yes I can ping from the nms to the loopback of the logical system,  
> but you are right, traffic is routed between nms and lr1 through R1  
> = it enters through an interface that belongs to R1 (the physical  
> router).
>
> Thanks for the suggestion! This looks promising. We will slightly  
> alter the network topology, in order to try this out.
>
> One question though: I see that you mention ri2, which is different  
> from the default routing instance. Does that actually matter? So far  
> we have not been using routing instances, but do you think we  
> actually need to setup one explicitly, within the logical-system?

One more question:

In your configuration I see only physical interfaces. To the extent of  
your knowledge, does it matter if the entry point is a logical sub- 
interface (unit) assigned to lr1, while the physical interface is used  
by R1?

Thanks,
Z.