From: Javier Tomé (fjtm@tid.es)
Date: Tue Sep 13 2005 - 12:32:55 GMT-3
The problem you are talking about is known as implicit redistribution.
Take a look at his link to an Alexei post on NMC (great post on
redistribution issue by the way). Search "implicit redistribution"...
http://bbs.netmasterclass.com/groupee/forums/a/tpc/f/4966010365/m/379105676
You will need to register, but the information is really worthy...
JT
Ali.Huang wrote:
>Thanks,Jens,Repeat again,
>R1(s0.1)---ospf(1.1.12.0/29)-----(s0)R2(e0)---eigrp(1.1.14.0/24
><javascript:dl('http://1.1.12.0/29-----s0R2e0---eigrp1.1.14.0/24',1);>)
>and R2 loopback0 1.1.2.2 <javascript:dl('http://1.1.2.2/',1);>
>First,no redistribute connected configured,
>R2:
>router ospf 10
>router-id 2.2.2.2 <javascript:dl('http://2.2.2.2/',1);>
>redistribute eigrp 1 metric-type 1 subnets route-map filtertag
>network 1.1.12.2 <javascript:dl('http://1.1.12.2/',1);>
>0.0.0.0<javascript:dl('http://0.0.0.0/',1);>area 0
>default-metric 150
>route-map CON permit 10
>match interface Loopback0
>R1 routing table,the cost of subnet(
>1.1.14.0/24<javascript:dl('http://1.1.14.0/24',1);>)
>was equal to 150 plus 100000000/1544. From this,it seems like redistribution
>by EIGRP,not connected directly.
>O E1 1.1.14.0/24 <javascript:dl('http://1.1.14.0/24',1);> [110/214] via
>1.1.12.2 <javascript:dl('http://1.1.12.2/',1);>, 00:00:01, Serial0.1
>and issues redistribute connected route-map CON.
>R2:
>router ospf 10
>router-id 2.2.2.2 <javascript:dl('http://2.2.2.2/',1);>
>redistribute connected metric-type 1 subnets route-map CON
>redistribute eigrp 1 metric-type 1 subnets route-map filtertag
>network 1.1.12.2 <javascript:dl('http://1.1.12.2/',1);>
>0.0.0.0<javascript:dl('http://0.0.0.0/',1);>area 0
>default-metric 150
>route-map CON permit 10
>match interface Loopback0
>
>And the 1.1.14.0/29 <javascript:dl('http://1.1.14.0/29',1);>disappeared in
>R1 routing table and filter.
>O E1 1.1.2.0/24 <javascript:dl('http://1.1.2.0/24',1);> [110/84] via
>1.1.12.2 <javascript:dl('http://1.1.12.2/',1);>, 00:00:02, Serial0.1
>
>next I add R2 e0 to route-map,
>route-map CON permit 10
>match interface Loopback0
>route-map CON permit 20
>match interface Ethernet0
>router ospf 10
>router-id 2.2.2.2 <javascript:dl('http://2.2.2.2/',1);>
>redistribute connected metric-type 1 subnets route-map CON
>redistribute eigrp 1 metric-type 1 subnets route-map filtertag
>network 1.1.12.2 <javascript:dl('http://1.1.12.2/',1);>
>0.0.0.0<javascript:dl('http://0.0.0.0/',1);>area 0
>default-metric 150
>Here is the R1 routing table.The cost is 84.
>O E1 1.1.2.0/24 <javascript:dl('http://1.1.2.0/24',1);> [110/84] via
>1.1.12.2 <javascript:dl('http://1.1.12.2/',1);>, 00:04:53, Serial0.1
>O E1 1.1.14.0/24 <javascript:dl('http://1.1.14.0/24',1);> [110/84] via
>1.1.12.2 <javascript:dl('http://1.1.12.2/',1);>, 00:00:19, Serial0.1
>It works,but the cost are different before do redistribute connected.
>The default-metric didn't force its cost to connected network,only working
>for routing protocol.
>Maybe the directly connection has high preference,becasue I do another
>scenario,they has equal AD,the lower cost wasn't in routing table when I
>change the cost by redistribute xxx metirc cost to control routing.
>
>On 9/13/05, Schulz, Dave <DSchulz@dpsciences.com> wrote:
>
>
>>I labbed up what Jens provided originally when I got home from work
>>today (cause I didn't believe it either). And.... it works just like he
>>says. Someone else mentioned that it happens to due to the RIB election
>>by having the best path. This makes since now, since a connected route
>>has a higher preference than a learned route.
>>
>>I then added the interfaces in the route-map (as described) and each one
>>was redistributed as they were added. Very interesting! I did not know
>>this. The question now is....does this happen with other types of
>>redistribution (other than just from eigrp to ospf). This could be
>>something to watch out for in the real lab.
>>
>>Thanks for the interesting lab scenario!
>>
>>
>>Dave Schulz
>>Email: dschulz@dpsciences.com
>>
>>
>>
>>-----Original Message-----
>>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
>>Godswill Oletu
>>Sent: Monday, September 12, 2005 11:12 PM
>>To: Jens Petter Eikeland; zero5291@gmail.com
>>Cc: ccielab@groupstudy.com; kumara.shunmugam@wipro.com
>>Subject: Re: redistribution between eigrp and ospf
>>
>>Jens,
>>
>>I do not know how clearer, I could be,
>>however..............................
>>
>>I never knew this was a task with some restrictions and the original
>>post
>>did not indicate that, as a result it was easy to deduce that he was
>>just
>>trying to resolve a reachability problem in his network. I was also
>>trying
>>to make it clear that the 'redistribute eigrp 1' statement was still in
>>effect and working as implemented.
>>
>>That said, depending on the restrictions in place, this can be resolved
>>by
>>various means, eg:
>>
>>1. network e0 under ospf process
>>2. summary address
>>3.
>>#route-map con permit 10
>>#match interface loopback0
>>#match interface ethernet0
>>
>>4.
>>#route-map con permit 10
>>#match interface loopback0
>>#
>>!
>>#route-map con permit 20
>>!
>>
>>
>>These are the four I can think of by heart at this time, there could be
>>other ways of making it to work depending on the restrictions in place.
>>
>>I have not had the time to lab these yet, but any of the above options
>>should work.
>>
>>HTH
>>Godwill Oletu
>>
>>----- Original Message -----
>>From: "Jens Petter Eikeland" <jenseike@start.no>
>>To: "'Godswill Oletu'" <oletu@inbox.lv>; <zero5291@gmail.com>
>>Cc: <ccielab@groupstudy.com>; <kumara.shunmugam@wipro.com>
>>Sent: Monday, September 12, 2005 10:26 PM
>>Subject: SV: redistribution between eigrp and ospf
>>
>>
>>No problem... I am cool. What you are telling below did not make much
>>sense
>>to me. I really do not understand what you are trying to say here. Try
>>be a
>>little more structured and not jump back and forth
>>
>>Jens Petter Eikeland
>>
>>-----Opprinnelig melding-----
>>Fra: nobody@groupstudy.com [mailto:nobody@groupstudy.com] Pe vegne av
>>Godswill Oletu
>>Sendt: 13. september 2005 00:25
>>Til: Jens Petter Eikeland; zero5291@gmail.com
>>Kopi: ccielab@groupstudy.com; kumara.shunmugam@wipro.com
>>Emne: Re: redistribution between eigrp and ospf
>>
>>take it easy.....life is not that hard.....
>>
>>try read my last post again at a latter time, when u would have cool
>>off.
>>the original post did not include "without network command", it sounded
>>more
>>
>>like someone wanting to know 'why' and a way to bypass the problem. I
>>was
>>just trying to help, so take a deep breath and relax, we are all here to
>>learn and not to throw punches....
>>
>>read this again from my last post:
>>
>>
>>
>>>'e0' was just a connected route (represented by 'C' in the routing
>>>
>>>
>>table)
>>
>>
>>>and not an 'eigrp 1' route on R2, hence it was filtered out by the
>>>'redistribute connected .....route-map...' statement.
>>>
>>>
>>>
>>Let me know if you agree or disagree with that and why?
>>
>>If the above statement is correct, then any route in the 'eigrp 1'
>>routing
>>table will be redistributed regardless of the route-map permitting the
>>connected interface 'lo0'. If one can get that particular route or some
>>fashion of it into the routing table with the "C", then 'eigrp 1' will
>>redistribute it regardless of what is in the 'redistribute
>>connected.....'
>>statement
>>
>>We seems to be out of luck, because the route '192.168.1.0<http://192.168.1.0>'
>>is a
>>connected
>>route "C" on R2, with an admin distance of 0 (It will be the best route
>>no
>>matter what is done). The best distance one can achieve via
>>redistibution or
>>
>>by using the distance command is the value of "1". This knowledge is
>>fundanmental in understanding what really took place and how to fix it.
>>
>>Another method is:
>>to summarize the network, ie ip address of 'e0' to a different boundary:
>>
>>eg
>>
>>#interface loopback0
>>#ip address 10.1.1.1 <http://10.1.1.1> 255.0.0.0 <http://255.0.0.0>
>>!
>>#interface ethernet0
>>#ip address 192.168.1.1 <http://192.168.1.1> 255.255.255.0<http://255.255.255.0>
>>#ip summary-address eigrp 1 192.168.0.0 <http://192.168.0.0> 255.255.0.0<http://255.255.0.0>
>>!
>>#router eigrp 1
>>#network 192.168.1.0 <http://192.168.1.0>
>>#
>>!
>>#interface serial0
>>#ip address 172.16.1.1 <http://172.16.1.1> 255.255.0.0<http://255.255.0.0>
>>!
>>#router ospf 1
>>#redistribute eigrp 1
>>#redistribute connected subnets route-map filter-connected
>>#network 172.16.0.0 <http://172.16.0.0> 0.0.255.255 <http://0.0.255.255>area 0
>>!
>>#route-map filter-connected permit 10
>>#match interface loopback0
>>#
>>
>>With this I was still able to achieve reachabilty without advertising
>>'e0'
>>network into ospf. I rely on 'redistribute eigrp 1' to pass the route
>>accross to R1.
>>
>>
>>----- Original Message -----
>>From: "Jens Petter Eikeland" <jenseike@start.no>
>>To: "'Godswill Oletu'" <oletu@inbox.lv>; <zero5291@gmail.com>
>>Cc: <ccielab@groupstudy.com>; <kumara.shunmugam@wipro.com>
>>Sent: Monday, September 12, 2005 4:15 PM
>>Subject: SV: redistribution between eigrp and ospf
>>
>>
>>
>>
>>>The task was to redistribute the loopback of router 2 without using
>>>network
>>>command. Then you need to use a red connected with a route map of
>>>
>>>
>>lopback.
>>
>>
>>>When you do this the route disapers (eigrp's e0)... why don't you test
>>>
>>>
>>it
>>
>>
>>>in
>>>a live rack. As you also can see from the ordernary question about
>>>
>>>
>>this
>>
>>
>>>that
>>>this is exactly what is happening... I don't think you can come here
>>>
>>>
>>and
>>
>>
>>>say
>>>that somebody are wrong if you don't test it and prove yourselfe. This
>>>
>>>
>>is
>>
>>
>>>a
>>>vel documented and I first learned it at a bootcamp with brian and
>>>
>>>
>>brian
>>
>>
>>>at
>>>internetworkexpert.
>>>
>>>Jens Petter Eikeland
>>>
>>>-----Opprinnelig melding-----
>>>Fra: Godswill Oletu [mailto:oletu@inbox.lv]
>>>Sendt: 12. september 2005 22:07
>>>Til: Jens Petter Eikeland; zero5291@gmail.com
>>>Kopi: ccielab@groupstudy.com; kumara.shunmugam@wipro.com
>>>Emne: Re: redistribution between eigrp and ospf
>>>
>>>Did you try...
>>>
>>>#router ospf 1
>>>#network <e0 network> <wildcard mask> area <ur appropriate area #>
>>>
>>>I understood what you were saying, but my point is, if a network is
>>>present
>>>in 'eigrp 1' table, 'redistribute eigrp 1' will redistribute it
>>>
>>>
>>regardless
>>
>>
>>>of the route-map connected filter.
>>>
>>>'e0' was just a connected route (represented by 'C' in the routing
>>>
>>>
>>table)
>>
>>
>>>and not an 'eigrp 1' route on R2, hence it was filtered out by the
>>>'redistribute connected .....route-map...' statement.
>>>
>>>HTH
>>>Godswill Oletu
>>>
>>>
>>>----- Original Message -----
>>>From: "Jens Petter Eikeland" <jenseike@start.no>
>>>To: "'Godswill Oletu'" <oletu@inbox.lv>; <zero5291@gmail.com>
>>>Cc: <ccielab@groupstudy.com>; <kumara.shunmugam@wipro.com>
>>>Sent: Monday, September 12, 2005 1:02 PM
>>>Subject: SV: redistribution between eigrp and ospf
>>>
>>>
>>>
>>>
>>>>I will try explain this again, because I know that I am right after I
>>>>
>>>>
>>have
>>
>>
>>>>tested this out. Me too thought this sounded far out when I first
>>>>
>>>>
>>learn
>>
>>
>>>>about it, and needed to see it with my own eyes before I belived it,
>>>>
>>>>
>>but
>>
>>
>>>>after tested this in the rack many times I know this is how it works,
>>>>
>>>>
>>so
>>
>>
>>>>please test it your selfe man...
>>>>
>>>>First of, e0 of r2 is in this scenario is not redistributed in to
>>>>
>>>>
>>eigrp,
>>
>>
>>>>but
>>>>is put in to eigrp with the network command. The hidden command that
>>>>
>>>>
>>the
>>
>>
>>>>router do when you enter any network in to the routin prosess with
>>>>
>>>>
>>the
>>
>>
>>>>network command is doing a hidden redistributed connected withs
>>>>
>>>>
>>include
>>
>>
>>>>all
>>>>the local networks that you entered in with the network command. This
>>>>
>>>>
>>is
>>
>>
>>>>how
>>>>it works :
>>>>
>>>>Router eigrp 1
>>>>Network (e0)
>>>>
>>>>When you enter this command the router put this networks in to the
>>>>routing
>>>>process by entering :
>>>>
>>>>Router eigrp 1
>>>>Redistribute connected route-map connected-local routes
>>>>Route-map connected-local-routes
>>>>
>>>>The router will never show this command in the config, but this is
>>>>
>>>>
>>what
>>
>>
>>>>the
>>>>router actually do.
>>>>
>>>>So
>>>>
>>>>When you then do a redistribute connected in to the other routing
>>>>
>>>>
>>process
>>
>>
>>>>(ospf here) with the command :
>>>>
>>>>Interface loopbac 0
>>>>Ip address xx.xx.xx.xx
>>>>
>>>>Router ospf 1
>>>>Redistribute eigrp 1 subnets
>>>>Redistribute connected subnets route-map loopback
>>>>Route-map connected permit 10
>>>>Match interface lo0
>>>>
>>>>When you do this, you will breake the redistribute connected that the
>>>>router
>>>>did for entering e0 in to the routing table(routing process of r2).
>>>>
>>>>
>>The
>>
>>
>>>>way
>>>>to fix this is to include this router in to this redistributing
>>>>
>>>>
>>process
>>
>>
>>>>like
>>>>this :
>>>>
>>>>Route-map loopbac
>>>>Match interface lo0 e0 (eigrp's e0 network)
>>>>
>>>>
>>>>I suggest you lab this up before you say that I am wrong, because
>>>>
>>>>
>>this is
>>
>>
>>>>how the routing process works in a cisco router when you do this kind
>>>>
>>>>
>>of
>>
>>
>>>>redistributing on the router. This goes only for when you do this.
>>>>
>>>>Jens P
>>>>
>>>>
>>>>
>>>>-----Opprinnelig melding-----
>>>>Fra: Godswill Oletu [mailto:oletu@inbox.lv]
>>>>Sendt: 12. september 2005 18:42
>>>>Til: Jens Petter Eikeland; zero5291@gmail.com
>>>>Kopi: ccielab@groupstudy.com; kumara.shunmugam@wipro.com
>>>>Emne: Re: redistribution between eigrp and ospf
>>>>
>>>>Ali,
>>>>
>>>>If you can, post configs from R1 & R2.
>>>>
>>>>Just redistributing connected with a route-map will not make 'e0' or
>>>>other
>>>>routes redistributed from eigrp to disappear from your routing table
>>>>
>>>>
>>or
>>
>>
>>>>the
>>>>routing table of R1. R2 will treat each statement one after the other
>>>>
>>>>
>>and
>>
>>
>>>>in
>>>>
>>>>a top to bottom fashion (redistribution will be treated first and
>>>>
>>>>
>>your
>>
>>
>>>>network statements will be rearranged and treated one after the other
>>>>after
>>>>the redistribute command).
>>>>
>>>>If the network of e0 is not been advertised by ospf separately (ie
>>>>
>>>>
>>you
>>
>>
>>>>are
>>>>not using 'network <e0 network> area <#>' under your ospf process or
>>>>
>>>>
>>any
>>
>>
>>>>command that will advertise it> and it is only been advertised under
>>>>
>>>>
>>your
>>
>>
>>>>eigrp process and u are relying on the 'redistribute' command to send
>>>>
>>>>
>>it
>>
>>
>>>>to
>>>>ospf, make sure you have 'redistribute eigrp <as#>.....' under your
>>>>
>>>>
>>ospf
>>
>>
>>>>process with the 'redistribute connected...' . Redistribute eigrp
>>>>
>>>>
>><as#>
>>
>>
>>>>will
>>>>
>>>>take care of all routes from eigrp including your 'e0' and the
>>>>'redistribute
>>>>
>>>>connected route-map' will filter your connected networks by the
>>>>
>>>>
>>route-map
>>
>>
>>>>and only advertise the ones that passed the test.
>>>>
>>>>Posting your configs will sort things out and put you in the right
>>>>track.....
>>>>
>>>>HTH
>>>>Godswill Oletu
>>>>
>>>>----- Original Message -----
>>>>From: "Jens Petter Eikeland" <jenseike@start.no>
>>>>To: <zero5291@gmail.com>
>>>>Cc: <ccielab@groupstudy.com>; <kumara.shunmugam@wipro.com>
>>>>Sent: Monday, September 12, 2005 11:50 AM
>>>>Subject: SV: redistribution between eigrp and ospf
>>>>
>>>>
>>>>
>>>>
>>>>>Hi
>>>>>
>>>>>
>>>>>
>>>>>What do you mean. This is how the router is behaving. Please lab it
>>>>>
>>>>>
>>up
>>
>>
>>>>>yourselfe. I have done it several times, and
>>>>>this happens every time
>>>>>
>>>>>
>>>>>
>>>>>Jens Petter Eikeland
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>_____
>>>>>
>>>>>Fra: Ali.Huang [mailto:zero5291@gmail.com]
>>>>>Sendt: 12. september 2005 17:48
>>>>>Til: Jens Petter Eikeland
>>>>>Kopi: ccielab@groupstudy.com; kumara.shunmugam@wipro.com
>>>>>Emne: Re: redistribution between eigrp and ospf
>>>>>
>>>>>
>>>>>
>>>>>Thanks your replies.
>>>>>
>>>>>I wonder if it is a default behavior,I doubt.
>>>>>
>>>>>If not redistribute connected ,I checked the routing table,and found
>>>>>
>>>>>
>>the
>>
>>
>>>>>metric of e0 doesn't like a connected network at all.
>>>>>
>>>>>So I feel doubt.
>>>>>
>>>>>
>>>>>On 9/12/05, Jens Petter Eikeland <jenseike@start.no> wrote:
>>>>>
>>>>>Ok, I have done some reachearc and found what is happening to the
>>>>>router -
>>>>>
>>>>>When you do redistribution here between eigrp and ospf (or any
>>>>>
>>>>>
>>other
>>
>>
>>>>>routing protocol.
>>>>>
>>>>>Router eigrp 1
>>>>>Network ( e0 )
>>>>>Redistribute ospf 1
>>>>>
>>>>>(the router will by default run this command)
>>>>>Redistribute connected subnets route-map conn
>>>>>
>>>>>Route-map default permit 10
>>>>>Match interface e0
>>>>>
>>>>>(This is what the router do when you add a network command
>>>>>to the routing process to add the nets in to the routing table
>>>>>automaticly)
>>>>>
>>>>>When you do a redistributed conected on the same router with a
>>>>>
>>>>>
>>match
>>
>>
>>>>>int
>>>>>Lo0
>>>>>
>>>>>Router ospf 1
>>>>>Redistribute connected subnet route-map conn
>>>>>
>>>>>Route-map conn
>>>>>Match int lo0
>>>>>
>>>>>When you do this you will loose the Ethernet interface that you
>>>>>advertised
>>>>>in to eigrp
>>>>>from the routing table and you will breake the redistribution
>>>>>
>>>>>
>>process
>>
>>
>>>>>that
>>>>>eigrp did on its connected interfaces. This is a default behaviour
>>>>>
>>>>>
>>of
>>
>>
>>>>>cisco
>>>>>routers.
>>>>>
>>>>>You can solve this by doing in ospf :
>>>>>
>>>>>Redistributed connected permit 10 route-map conn
>>>>>
>>>>>Route-map conn
>>>>>Match interface e0
>>>>>
>>>>>In addition to the connected loopback you redistributed in earlier
>>>>>
>>>>>
>>>>>
>>>>>Hope this explain this for you. This is a behaivur that the router
>>>>>
>>>>>
>>has,
>>
>>
>>>>>and
>>>>>this is something you need to think of when you do redistribution on
>>>>>
>>>>>
>>a
>>
>>
>>>>>border router
>>>>>
>>>>>Jens P
>>>>>
>>>>>
>>>>>-----Opprinnelig melding-----
>>>>>Fra: nobody@groupstudy.com [mailto:nobody@groupstudy.com] Pe vegne
>>>>>
>>>>>
>>av
>>
>>
>>>>>Ali.Huang
>>>>>Sendt: 12. september 2005 13:35
>>>>>Til: Cisco certification
>>>>>Emne: redistribution between eigrp and ospf
>>>>>
>>>>>hi,group,
>>>>>Topo:R1---ospf-----(s0)R2(e0)---eigrp
>>>>>I do bi-direction redistribution.work well.and the subnet of e0 was
>>>>>diaplayed in R1 routing table.But when I want to redistribute
>>>>>
>>>>>
>>loopback0
>>
>>
>>>>>of
>>>>>R2 into ospf domain,use the following clauses;
>>>>>route-map CON permit 10
>>>>>match interface Loopback0
>>>>>router ospf 10
>>>>>redistribute connected metric-type 1 metric 100 subnets route-map
>>>>>
>>>>>
>>CON
>>
>>
>>>>>The subnet of e0 disappeares from R1 routing table,and the loopback0
>>>>>
>>>>>
>>of
>>
>>
>>>>>R2
>>>>>OK.If removes the redistribute connected,OK.it come back.who can
>>>>>
>>>>>
>>tell me
>>
>>
>>>>>why?
>>>>>
>>>>>THX.
>>>>>Ali.huang
>>>>>
>>>>>
>>>>>
>>>>>
>>_______________________________________________________________________
>>
>>
>>>>>Subscription information may be found at:
>>>>>http://www.groupstudy.com/list/CCIELab.html
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>--
>>>>>THX.
>>>>>Ali.huang
>>>>>
>>>>>
>>>>>
>>>>>
>>_______________________________________________________________________
>>
>>
>>>>>Subscription information may be found at:
>>>>>http://www.groupstudy.com/list/CCIELab.html
>>>>>
>>>>>
>>_______________________________________________________________________
>>Subscription information may be found at:
>>http://www.groupstudy.com/list/CCIELab.html
>>
>>_______________________________________________________________________
>>Subscription information may be found at:
>>http://www.groupstudy.com/list/CCIELab.html
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