Re: BGP conditional adv??

OK. I think I get it. Correct me if I'm wrong:

if my agg route has {100,300} which are AS numbers of R1 and R3, R1
and R3 will discard that agg prefix cause they see it's own AS number.
When I do this, on the R2 which is originator of agg rute:

ip as-patch acl 1 per ^300$
route-map XXX
   match as-patch 1
router bgp 200
   agg-add 3.1.0.0 255.255.240.0 summ-only as-set adv-map XXX

I'm actually permitting only ASN 300 in AS_PATH, so R1 will process
agg route and install it in BGP table cause it doesn't see it's AS
number. R3 will discard it. Is this correct? Is this the functionality
of adv-map with aggregation?

Regards

On Thu, Feb 25, 2010 at 2:47 PM, Tolulope Ogunsina <togunsina_at_gmail.com> wrote:
> Hi,
> The advertise-map in aggregate address command is different from the
> advertise map in conditional advertisements.
> In aggregate address, the advertise-map argument is the "Name of the
> route map used to select the routes to create AS_SET origin
> communities"
>
> With that said, I do NOT fully understand the scenario you're
> describing. Please shed some more light.
>
> On 2/25/10, Ivan Hrvatska <ivanzghr_at_gmail.com> wrote:
>> Oh, yea. I didn't read carefully :) First bullet will be done by
>> default. Third bullet will also be done by default. So, the second
>> bullet is actually going through the task on reverse way. If 1.0.0.0
>> is DOWN, nothing is going to be advertised, and if it is UP, only
>> 2.0.0.0 will be advertised. OK. I get it. I was confused by the way
>> the task is given.
>>
>> As I go further through the BGP i have one more issue.
>> One task:
>>
>> R1------R2-------R3
>>
>> R3 has couple of specific nets which are aggregated by R2. R1 only
>> gets aggregate prefix without atomic-agg attribute (summary-only and
>> as-set is used). The aggregation should be configured such that R1 in
>> AS 100 is the only AS that recivies agg route. R3 or future peer
>> neighbors should NOT receive the agg route.
>> Solution:
>> ip as-path access-list 1 permit ^300$
>> route-map TST per 10
>> match as-path 1
>> agg 3.1.0.0 255.255.240.0 as-set summ-only adv-map TST
>>
>> First, I planned to solve this task with community no-export. R2 sets
>> that comm to the agg route and send it to R1.
>> I don't het what this route-map exactly does in this case? as-path acl
>> matches prefixes originated in AS 300. What else in combination with
>> agg-add command?
>>
>> regards
>>
>> On Thu, Feb 25, 2010 at 11:20 AM, Tolulope Ogunsina <togunsina_at_gmail.com>
>> wrote:
>>> The solution means advertise 2.0.0.0 if (and only if) 1.0.0.0 exists
>>> which also means if 1.0.0.0 does NOT exist, do NOT advertise 2.0.0.0.
>>>
>>> On 2/25/10, Ivan Hrvatska <ivanzghr_at_gmail.com> wrote:
>>>> 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?
>>>>>>
>>>>>>
>>>>>> Blogs and organic groups at http://www.ccie.net
>>>>>>
>>>>>> _______________________________________________________________________
>>>>>> Subscription information may be found at:
>>>>>> http://www.groupstudy.com/list/CCIELab.html
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Best Regards,
>>>>>
>>>>> Tolulope.
>>>>>
>>>>
>>>
>>>
>>> --
>>> Best Regards,
>>>
>>> Tolulope.
>>
>>
>> Blogs and organic groups at http://www.ccie.net
>>
>> _______________________________________________________________________
>> Subscription information may be found at:
>> http://www.groupstudy.com/list/CCIELab.html
>>
>>
>>
>>
>>
>>
>>
>>
>
>
> --
> Best Regards,
>
> Tolulope.

Blogs and organic groups at http://www.ccie.net
Received on Thu Feb 25 2010 - 16:35:48 ART