Re: Tag BGP external routes?

Could be, but it is better to make one last check. Can you post also:
- eigrp topology
- ospf and eigrp config sections
- route-map

-m.

On Tue, Mar 23, 2010 at 10:41 AM, Ivan Hrvatska <ivanzghr_at_gmail.com> wrote:

> Hmm...This is my OSPF database output:
>
> Type-5 AS External Link States
>
> Link ID ADV Router Age Seq# Checksum Tag
> 9.9.33.0 9.9.8.8 4 0x80000001 0x0097B3 0
> 99.99.1.0 9.9.8.8 5 0x80000001 0x0014A3 254
> 99.99.2.0 9.9.8.8 5 0x80000001 0x0009AD 254
> 99.99.3.0 9.9.8.8 5 0x80000001 0x00FDB7 254
> 99.99.4.0 9.9.8.8 5 0x80000001 0x00F2C1 254
> 99.99.5.0 9.9.8.8 5 0x80000001 0x00E7CB 254
> 198.3.0.0 9.9.8.8 5 0x80000001 0x008635 0
>
> This is an output on another SW in OSPF domain.
> Software in SW2 is:
> c3750-advipservicesk9-mz.122-35.SE5
>
> Could be a bug?
>
>
> On Tue, Mar 23, 2010 at 10:20 AM, Mirco Orlandi <mirco.orlandi_at_gmail.com>
> wrote:
> > 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 - 11:00:41 ART