Re: Tag BGP external routes?

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 - 10:41:18 ART