Re: BGP conditional adv??

Of course. Totally agree with that...

On Fri, Feb 26, 2010 at 11:27 PM, Narbik Kocharians <narbikk_at_gmail.com> wrote:
> Hey...... NO HUMOR, NO LIFE, NO NUMBER.
>
> On Fri, Feb 26, 2010 at 2:01 PM, Ivan Hrvatska <ivanzghr_at_gmail.com> wrote:
>>
>> Ooh, very funny :)) Specially 10 days before my exam :))
>>
>> On Fri, Feb 26, 2010 at 9:22 PM, Narbik Kocharians <narbikk_at_gmail.com>
>> wrote:
>> > Guys i know it does work, he is referring to one of my labs, i was
>> > joking
>> > with him, because he used patch instead of path.
>> >
>> > On Fri, Feb 26, 2010 at 2:25 AM, Tolulope Ogunsina <togunsina_at_gmail.com>
>> > wrote:
>> >>
>> >> Yes, I just did.
>> >> Assume we have R1, R2,R3 and R4 in AS 1, 2,3 and 4 respectively
>> >> R1 -- R4 --- R3
>> >> |
>> >> R2
>> >>
>> >> R1, R2, and R3 advertise 150.1.x.0/24 into bgp where x is the router
>> >> number.
>> >>
>> >> R4 aggregates the routes to 150.1..0.0/16 with as-set attribute.
>> >> By default, none of the routers get the update anymore since their
>> >> individual routes are a part of the summary.
>> >>
>> >> Using advertise map, we want to make R1 and R3 get the summary; so we
>> >> only advertise the attributes of the prefix form R2 with the summary.
>> >> Using as path access-lists and route-maps on R4 we have,
>> >>
>> >> ip as-path access-list 1 permit ^2$
>> >> route-map adv permit 10
>> >> match as-path 1
>> >>
>> >> router bgp 4
>> >> aggregate-address 150.1.0.0 255.255.0.0 as-set summary-only
>> >> advertise-map
>> >> adv
>> >>
>> >> Now, R1 and R3 get the summary, R2 doesn't because its AS number is
>> >> carried along with the summary
>> >>
>> >> R1(config-router)#do sh ip bg | i 150.1.0.0
>> >> *> 150.1.0.0 192.168.1.4 0 0 4 2 i
>> >>
>> >> R2(config-router)#do sh ip bg | i 150.1.0.0
>> >> R2(config-router)#
>> >>
>> >> HTH,
>> >>
>> >> On 2/26/10, Ruhann <groupstudy_at_ru.co.za> wrote:
>> >> > Have you labbed this?
>> >> >
>> >> > On Fri, Feb 26, 2010 at 10:54 AM, Tolulope Ogunsina
>> >> > <togunsina_at_gmail.com>
>> >> > wrote:
>> >> >> Yes, for conditional route advertisement.
>> >> >>
>> >> >> Advertise-maps in conditional advertisement and Route aggregation
>> >> >> (using the aggregate-address command) perform two entirely different
>> >> >> functions.
>> >> >>
>> >> >> In the latter, the advertise map specifies the "Name of the route
>> >> >> map
>> >> >> used to select the routes to create AS_SET origin communities."
>> >> >>
>> >> >> On 2/26/10, Ruhann <groupstudy_at_ru.co.za> wrote:
>> >> >>> Conditional Route advertisement is meant to watch a route. I am not
>> >> >>> so
>> >> >>> sure it will work the way you want, matching a AS-Path filter..
>> >> >>>
>> >> >>> It watches a Prefix in the table (the watch route), and if that
>> >> >>> prefix
>> >> >>> dissapear it then advertises another prefix (the advertise prefix)
>> >> >>>
>> >> >>> On Thu, Feb 25, 2010 at 5:35 PM, Ivan Hrvatska <ivanzghr_at_gmail.com>
>> >> >>> wrote:
>> >> >>>> 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
>> >> >>>>
>> >> >>>>
>> >> >>>>
>> >> >>>> _______________________________________________________________________
>> >> >>>> Subscription information may be found at:
>> >> >>>> http://www.groupstudy.com/list/CCIELab.html
>> >> >>>>
>> >> >>>>
>> >> >>>>
>> >> >>>>
>> >> >>>>
>> >> >>>>
>> >> >>>>
>> >> >>>>
>> >> >>>
>> >> >>>
>> >> >>>
>> >> >>> --
>> >> >>> <ruhann>
>> >> >>> www.routing-bits.com
>> >> >>>
>> >> >>>
>> >> >>> 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.
>> >> >>
>> >> >
>> >> >
>> >> >
>> >> > --
>> >> > <ruhann>
>> >> > www.routing-bits.com
>> >> >
>> >>
>> >>
>> >> --
>> >> 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
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >>
>> >
>> >
>> >
>> > --
>> > Narbik Kocharians
>> > CCSI#30832, CCIE# 12410 (R&S, SP, Security)
>> > www.MicronicsTraining.com
>> > Sr. Technical Instructor
>> > YES! We take Cisco Learning Credits!
>> > Training And Remote Racks available
>> >
>
>
>
> --
> Narbik Kocharians
> CCSI#30832, CCIE# 12410 (R&S, SP, Security)
> www.MicronicsTraining.com
> Sr. Technical Instructor
> YES! We take Cisco Learning Credits!
> Training And Remote Racks available

Blogs and organic groups at http://www.ccie.net
Received on Sun Feb 28 2010 - 22:45:51 ART