Re: Tag BGP external routes?

ok Ivan,
AS253 is what I supposed.

SW2(ospf1+eigrpAS100)--BB1(eigrpAS100+bgpAS253)--BB2(bgpAS254)

BB1 redistribute bgpAS253 into eigrpAS100. All bgp routes that BB1 learn
from BB2 will be tagged 254 during redistribution (Ryan point). Tag swap
254->999 work fine in my lab with route-map I posted (I see tag 999 in "show
ip ospf database").

Cisco IOS Software, 2600 Software (C2691-ADVIPSERVICESK9-M), Version
12.4(15)T8
-mirco.

On Tue, Mar 23, 2010 at 9:40 AM, Ivan Hrvatska <ivanzghr_at_gmail.com> wrote:

> SW2----------BB1(AS253)-----------BB2 (AS254)
>
> SW2 -device I have to configure the task on
> BB1 - my EIGRP neighbor and BGP router in AS253
> BB2 - eBGP peer with BB1
>
> So, to simulate the task BB2 is in AS253 and has eBGP session with BB1
> so that BB1 can redistribute prefixes into EIGRP which are received
> via eBGP session, right?
>
> Next, when BB1 redistributes those prefixes into EIGRP my SW2 receives
> them with route tag 254, which is AS number of originator of those
> prefixes, right?
>
> So, now I should match any tag other than 253 cause I know that my
> EIGRP neighbor is in AS 253 and it has to receive prefixes from
> another AS for that prefixes to be external, right?
> When I issue show ip route 99.99.1.0 and see that route tag is 254, I
> match that tag. But, set tag in the same route map statement doesn't
> work. It won't change tag. In OSPF domain I still see those prefixes
> with original tag 254.
>
> When I issue set tag command under redistribution eigrp command (when
> I redistribute from EIGRP into OSPF), tag is changed, but it is
> changed for ALL redistributed EIGRP routes, and that is on the goal.
>
> Regards
>
> On Mon, Mar 22, 2010 at 5:25 PM, Mirco Orlandi <mirco.orlandi_at_gmail.com>
> wrote:
> > Ivan, by your show on SW2 I see you are using "tag 200" inside
> > redistribution statement.
> > Result should be:
> > - change tag to 999 for routes with tag 254
> > - set tag 200 to others
> >
> > It works fine on my lab.
> >
> > What do you mean by "I know that my EIGRP neighbor is in AS 253"?
> > You have ospf 1, eigrp AS100, and a remote bgp peer with AS254. Is AS253
> the
> > local BGP AS of SW2 eigrp neighbor?
> >
> > -mirco.
> >
> > On Mon, Mar 22, 2010 at 4:40 PM, Ivan Hrvatska <ivanzghr_at_gmail.com>
> wrote:
> >>
> >> Well, let's say that my EIGRP neighbor, which is also BGP router,
> >> recives some prefixes via eBGP session and redistribute them into
> >> EIGRP. My router (SW2) recives that prefixes via EIGRP and EIGRP has
> >> originator's AS number as route tag:
> >>
> >> SW2#sh ip ro 99.99.1.0
> >> Routing entry for 99.99.1.0/24
> >> Known via "eigrp 100", distance 170, metric 2560000512
> >> Tag 254, type external
> >> Redistributing via ospf 1, eigrp 100
> >> Advertised by ospf 1 subnets tag 200 route-map TAG
> >> Last update from 9.9.33.254 on Vlan33, 00:04:02 ago
> >> Routing Descriptor Blocks:
> >> * 9.9.33.254, from 9.9.33.254, 00:04:02 ago, via Vlan33
> >> Route metric is 2560000512, traffic share count is 1
> >> Total delay is 20 microseconds, minimum bandwidth is 1 Kbit
> >> Reliability 1/255, minimum MTU 1 bytes
> >> Loading 1/255, Hops 1
> >> Route tag 254
> >>
> >> If I use that tag 254 in my route-map like this, because I know that
> >> my EIGRP neighbor is in AS 253:
> >>
> >> !
> >> route-map TAG permit 10
> >> match tag 254
> >> set tag 999
> >> !
> >> route-map TAG permit 90
> >> !
> >>
> >> That prefixes go into OSPF without changed tag ??!! set tag 999 didn't
> >> change tag. Why?
> >> If I put tag command under redistribute command then all prefixes will
> >> be tagged with 999.
> >> Right?
> >>
> >> On Mon, Mar 22, 2010 at 3:50 PM, Mirco Orlandi <mirco.orlandi_at_gmail.com
> >
> >> wrote:
> >> > Hi Ivan,
> >> > using "tag" inside redistribution statement, you are setting tag 999
> to
> >> > all
> >> > routes you are redistributing.
> >> >
> >> > To match the task requirement, you have to set tag 999 only to
> external
> >> > eigrp routes
> >> > On R1:
> >> >
> >> > route-map set-tag permit 10
> >> > match route-type external
> >> > set tag 999
> >> >
> >> > route-map set-tag permit 20
> >> >
> >> > router ospf 1
> >> > redistribute eigrp 1 subnets route-map set-tag
> >> >
> >> >
> >> >
> >> > but..., if you prefere, you can set tag 999 inside statement and
> >> > override
> >> > the tag for non-external routers:
> >> >
> >> > route-map set-tag permit 10
> >> > match route-type external
> >> >
> >> > route-map set-tag permit 20
> >> > set tag 1
> >> >
> >> > router ospf 1
> >> > redistribute eigrp 1 subnets tag 999 route-map set-tag
> >> >
> >> >
> >> > I labbed it with Adv.IP.Svcs 12.4(15)T8
> >> > I think first solution is more common, and clear.
> >> >
> >> > -mirco.
> >> >
> >> > On Mon, Mar 22, 2010 at 2:33 PM, Ivan Hrvatska <ivanzghr_at_gmail.com>
> >> > wrote:
> >> >>
> >> >> Tagging eBGP prefixes. Hmm...I see why are you confused. I'm also
> >> >> confused. Cause when you redistribute BGP into EIGRP those prefixes
> >> >> are external to EIGRP. After that you redistribute them into OSPF.
> >> >> During that redistribution they will be tagged using match route-type
> >> >> external no matter what protocol originates that prefixes...
> >> >>
> >> >> Well, let's just say that task is "tag all external BGP prefixes with
> >> >> tag 999". ?
> >> >>
> >> >> On Mon, Mar 22, 2010 at 1:26 PM, Marc La Porte
> >> >> <marc.a.laporte_at_gmail.com>
> >> >> wrote:
> >> >> > Other question: do you mean tagging eBGP prefixes? Or prefixes
> which
> >> >> > were
> >> >> > redistributed into BGP?
> >> >> >
> >> >> > On Mon, Mar 22, 2010 at 13:04, Ivan Hrvatska <ivanzghr_at_gmail.com>
> >> >> > wrote:
> >> >> >>
> >> >> >> How do you tag external BGP prefixes? Let's say you have two
> routers
> >> >> >> in EIGRP domain. One router (R2) runs EIGRP and BGP with some
> peers.
> >> >> >> Other router runs EIGRP and it is also ASBR OSPF router (R1). On
> R1
> >> >> >> you redistribute EIGRP into OSPF and during redistribution you
> have
> >> >> >> to
> >> >> >> tag BGP external routes with some tag. Is this enough:
> >> >> >>
> >> >> >> route-map MAP per 10
> >> >> >> match route-type external
> >> >> >>
> >> >> >> route-map MAP per 100
> >> >> >>
> >> >> >> router ospf 1
> >> >> >> redistribute eigrp 1 subnets tag 999 route-map MAP
> >> >> >>
> >> >> >> ??
> >> >> >>
> >> >> >>
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> >> >> >>
> >> >> >>
> >> >> >>
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Received on Tue Mar 23 2010 - 10:20:41 ART