Re: BGP conditional adv??

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 <http://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