Re: Redistribution Problem

http://www.cisco.com/en/US/tech/tk365/technologies_q_and_a_item09186a008012dac4.shtml

Q. If there are two EIGRP processes that run and two equal paths are
learned, one by each EIGRP process, do both routes get installed?

*A.* No, only one route is installed. The router installs the route that was
learned through the EIGRP process with the lower Autonomous System (AS)
number. In Cisco IOS Software Releases earlier than 12.2(7)T, the router
installed the path with the latest timestamp received from either of the
EIGRP processes. The change in behavior is tracked by Cisco bug ID
CSCdm47037.

On Fri, Aug 27, 2010 at 10:23 PM, CCIE KID <eliteccie_at_gmail.com> wrote:

> hey this problem seems fishy
> i have done ur topology n observed the same thing
> wats happening
> sumone clear my mind!!!!
>
> On Fri, Aug 27, 2010 at 10:17 PM, Kambiz Agahian <aussiecert_at_gmail.com
> >wrote:
>
> > The one with a lower number or the one to be seen first?
> >
> > Kambiz Agahian
> > CCIE Instructor/Consultant
> > M.Eng Telecom, CCIE# 25341, CCSI# 33326, MCSE, MCSA
> >
> > On Fri, Aug 27, 2010 at 9:43 AM, HEMANTH RAJ <hemanthrj_at_gmail.com>
> wrote:
> >
> > > yes Vince u r right it chooses the one with a lower Autonomous system
> > > .Experts pls guide me for this question.
> > >
> > >
> > >
> > > On Fri, Aug 27, 2010 at 11:35 AM, Vince Librandi <
> > > vlibrandi_at_internode.on.net
> > > > wrote:
> > >
> > > > Woops forgot to add the answer to your question.
> > > >
> > > > The router will only choose use the routes for a prefix from one
> > routing
> > > > protocol because that way it can guarantee at least for that AS it
> has
> > a
> > > > loop free path for the prefix (of course redistribution can negate
> > that).
> > > > But if the router where to install one route from one AS and another
> > from
> > > a
> > > > second AS it wouldn't be able to be sure that the path doesn't loop
> > > > somewhere as the two AS's don't share routing information.
> > > >
> > > > So it looks like the router chooses the lowest AS number when the
> > prefix
> > > > length and AD are the same for a prefix.
> > > >
> > > >
> > > > On 27/08/2010 3:05 PM, Vince Librandi wrote:
> > > >
> > > >> Hi Hemanth,
> > > >>
> > > >> I just lab'ed up your set up and got the same affect. Looks like
> when
> > > you
> > > >> have two EIGRP process and the metric is the same and the AD on the
> > > route is
> > > >> the same the router chooses the process with the lowest AS number.
> > Just
> > > to
> > > >> prove it I configured another EIGRP process (AS 50) on the R5-R4
> link
> > > and
> > > >> the router choose that path instead.
> > > >>
> > > >> R5(config-router)#do sh ip ei top
> > > >> IP-EIGRP Topology Table for AS(100)/ID(10.1.45.5)
> > > >>
> > > >> Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
> > > >> r - reply Status, s - sia Status
> > > >>
> > > >> P 1.1.1.1/32, 0 successors, FD is Inaccessible
> > > >> via 10.1.35.3 (3097600/2585600), Serial0/1
> > > >>
> > > >> IP-EIGRP Topology Table for AS(200)/ID(1.1.1.2)
> > > >>
> > > >> Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
> > > >> r - reply Status, s - sia Status
> > > >>
> > > >> P 1.1.1.1/32, 0 successors, FD is Inaccessible
> > > >> via 10.1.45.4 (3097600/2585600), Serial0/0
> > > >>
> > > >> IP-EIGRP Topology Table for AS(50)/ID(10.1.45.5)
> > > >>
> > > >> Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
> > > >> r - reply Status, s - sia Status
> > > >>
> > > >> P 1.1.1.1/32, 1 successors, FD is 3097600
> > > >> via 10.1.45.4 (3097600/2585600), Serial0/0
> > > >>
> > > >>
> > > >>
> > > >> but if both links are in the same AS then I get the load balancing
> > > >>
> > > >> R5(config-router)#do sh ip ei top
> > > >> IP-EIGRP Topology Table for AS(100)/ID(10.1.45.5)
> > > >>
> > > >> Codes: P - Passive, A - Active, U - Update, Q - Query, R - Reply,
> > > >> r - reply Status, s - sia Status
> > > >>
> > > >> P 1.1.1.1/32, 2 successors, FD is 3097600
> > > >> via 10.1.35.3 (3097600/2585600), Serial0/1
> > > >> via 10.1.45.4 (3097600/2585600), Serial0/0
> > > >>
> > > >> Looks like this is the way the routing table chooses between routes
> > > handed
> > > >> to it from different processes.
> > > >>
> > > >> Must see if OSPF does the same thing.
> > > >>
> > > >> Regards
> > > >>
> > > >> Vince
> > > >>
> > > >>
> > > >> On 27/08/2010 1:21 PM, HEMANTH RAJ wrote:
> > > >>
> > > >>> s0/1 s0/0
> > > >>> R2-------------------R3\s 0/2
> > > >>> | | \
> > > >>> |s0/0 s0/3 | \
> > > >>> | | \ R1-loo 0
> > > >>> 1.1.1.1/24
> > > >>> | | \ s 0/0 R1-loo 1
> > > >>> 11.11.11.11/24
> > > >>> | | \
> > > >>> | | / R5 R2-loo o
> > > 2.2.2.2
> > > >>> /24
> > > >>> | | / R2-loo 1
> > > >>> 22.22.22.22/24
> > > >>> | | / s 0/1
> > > >>> | | /
> > > >>> | s0/0 | /
> > > >>> | s0/3 | /s0/2
> > > >>> R1-------------------R4
> > > >>> s0/1 s0/0
> > > >>>
> > > >>>
> > > >>>
> > > >>>
> > > >>>
> > > >>> I'm running ospf area 0 on R1,R2,R3 s 0/0,R4 s0/0
> > > >>>
> > > >>> R3 s0/3 ospf area 20
> > > >>> R4 s0/3 ospf area 20
> > > >>>
> > > >>> R3 s0/2 eigrp AS 100
> > > >>> R5 s0/0 eigrp AS 100
> > > >>>
> > > >>> R4 s0/2 eigrp AS 200
> > > >>> R5 s0/1 eigrp AS 200
> > > >>>
> > > >>>
> > > >>> I have done mutual redistribution on R3 between OSPF and EIGRP 100
> > > >>>
> > > >>> I have done mutual redistribution on R4 between OSPF and EIGRP 200
> > > >>>
> > > >>> Every route can ping every other route
> > > >>>
> > > >>> But when i check on R5 routing table I'm learning R1's loopback0
> via
> > R3
> > > >>>
> > > >>> But as per the logic it should load balance between R3 and R4 but
> it
> > is
> > > >>> choosing only R3
> > > >>> and when i check on R5 topology table it shows the route via R4 is
> > > >>> inaccessible
> > > >>>
> > > >>> I have reidstributed from opsf to eigrp with same metric on both R3
> > and
> > > >>> R4
> > > >>>
> > > >>> R3
> > > >>> router eigrp 100
> > > >>> redis ospf 1 met 1 1 1 1 1
> > > >>>
> > > >>> R4
> > > >>> router eigrp 200
> > > >>> redis ospf 1 met 1 1 1 1 1
> > > >>>
> > > >>> But still R5 is choosing path via R3 and not loadbalancing between
> R3
> > > and
> > > >>> R4
> > > >>>
> > > >>> Can anyone help me out of this issue???
> > > >>>
> > > >>
> > > >>
> > > >> Blogs and organic groups at http://www.ccie.net
> > > >>
> > > >>
> > _______________________________________________________________________
> > > >> Subscription information may be found at:
> > > >> http://www.groupstudy.com/list/CCIELab.html
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >>
> > > >
> > >
> > >
> > > --
> > > Problems arise Bcoz we talk,prblms r not solve bcoz we dont talk So gud
> r
> > > bad talk to ur affectionate one's freely
> > >
> > > Urs Friendly,
> > > HP HEMANTH RAJ
> > >
> > >
> > > Blogs and organic groups at http://www.ccie.net
> > >
> > > _______________________________________________________________________
> > > Subscription information may be found at:
> > > http://www.groupstudy.com/list/CCIELab.html
> >
> >
> > Blogs and organic groups at http://www.ccie.net
> >
> > _______________________________________________________________________
> > Subscription information may be found at:
> > http://www.groupstudy.com/list/CCIELab.html
> >
> >
> >
> >
> >
> >
> >
> >
>
>
> --
> With Warmest Regards,
>
> CCIE KID
> IN PURSUIT OF CCIE
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Fri Aug 27 2010 - 23:07:47 ART