Re: BGP conditional adv??

Yes, that is true. But shouldn't solution be: if 1.0.0.0/8 is DOWN, do
NOT advertise 2.0.0.0:

in solution in route-map EXIST you are matching 1.0.0.0, which means,
if 1.0.0.0 exist in RIB, advertise what you permit in route-map ADV,
and in route-map ADV you permit 2.0.0.0. That's what is confusing to
me.

On Thu, Feb 25, 2010 at 9:32 AM, Tolulope Ogunsina <togunsina_at_gmail.com> wrote:
> Hi Ivan,
> From the question,
>
> - if both nets 1.0.0.0 and 2.0.0.0 are up, R1 should advertise them both
> - if 1.0.0.0/8 is DOWN, R1 should not advertise 2.0.0.0/8 to R3
> - if 2.0.0.0/8 is DOWN, R1 should only advertise net 1.0.0.0/8 to R3
>
> network 2.0.0.0/8 is dependent on 1.0.0.0/8. (second requirement).
> 1st and third requirements are the default behavior of the BGP process.
>
> Hence the solution only focuses on the second requirement.
>
> HTH,
>
> On 2/24/10, Ivan Hrvatska <ivanzghr_at_gmail.com> wrote:
>> Hi experts,
>>
>> I have some difficulties to catch this scenario with BGP conditional adv:
>>
>> R1-----------R2
>> |
>> |
>> R3
>>
>> R1 has lo0 1.1.1.1/8, R2 has Lo0 2.2.2.2/8 and R3 has also Lo0
>> 3.3.3.3/8. All RTs are in same AS and all of them advertise their
>> loopbacks.
>> Task is next:
>> - if both nets 1.0.0.0 and 2.0.0.0 are up, R1 should advertise them both
>> - if 1.0.0.0/8 is DOWN, R1 should not advertise 2.0.0.0/8 to R3
>> - if 2.0.0.0/8 is DOWN, R1 should only advertise net 1.0.0.0/8 to R3
>>
>> Solution on R1:
>> acl 1 permit 1.0.0.0 0.255.255.255
>> acl 2 permit 2.0.0.0 0.255.255.255
>>
>> route-map ADV per 10
>> match ip add 2
>> route-map EXIST per 10
>> match ip add 1
>>
>> router bgp 100
>> neighbor R3 adv-map ADV exist-map EXIST
>>
>> So, from my point of view this task should do next:
>> - if 1.0.0.0/8 is UP (2.0.0.0/8 can also be UP) advertise 2.0.0.0/8 to
>> R3 (task asks you to NOT advertise)
>> - if 1.0.0.0/8 is DOWN (2.0.0.0/8 can also be DOWN), do not advertise
>> anything
>>
>> This solution is correct, but I don't get the logic?
>>
>>
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>>
>>
>
>
> --
> Best Regards,
>
> Tolulope.

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Received on Thu Feb 25 2010 - 11:13:59 ART