From: Omer Ansari (omer@xxxxxxxxxx)
Date: Mon Aug 05 2002 - 17:48:23 GMT-3
Dmitry,
I had almost exactly the same reasoning as yours for each point you have
raised, though I had a question about one thing you mentioned:
> Router creates summary to Null automaticaly, and this aggregate will be
> propagated
> to area 1 ONLY, it will NOT appears in any OTHER area of your ospf domain.
if R4 was connected to another area, say Area3, i think the area 0 range
XXX command would send a summarized area towards A3 also right?
Also, i have heard that the area 0 range XX works on some IOSs and doesnt
on the rest...so i'm a little wary of it.
Armand,
To add to the list of solutions, I personally prefer 2 ospf processes on
the ASBR b/c :
. changes only on ASBR, and
. no extra tunnel network routes crapping up the route table
on R6:
!
router ospf 10
log-adjacency-changes
summary-address 135.4.24.0 255.255.255.0
redistribute igrp 10 subnets
network 135.4.36.6 0.0.0.0 area 1
!
router ospf 20
log-adjacency-changes
summary-address 135.4.36.0 255.255.255.0
summary-address 135.4.24.0 255.255.255.0
redistribute ospf 10 subnets
!
router igrp 10
redistribute ospf 20 metric 1500 1500 254 1 1500
passive-interface Ethernet0/0
network 135.4.0.0
!
on R5:
R5#si
Gateway of last resort is not set
135.4.0.0/24 is subnetted, 3 subnets
I 135.4.24.0 [100/8266] via 135.4.56.6, 00:00:43, Ethernet0/0
I 135.4.36.0 [100/8266] via 135.4.56.6, 00:00:43, Ethernet0/0
C 135.4.56.0 is directly connected, Ethernet0/0
note however, that this rides on the premise that ospf process 20 would
produce summary routes in the route table of R6 which would then be
redistributed into igrp 10.
so though elegant, this maynot work with your requirements.
regards,
Omer
On Mon, 5 Aug 2002, Volkov, Dmitry (Toronto - BCE) wrote:
> William,
>
> I don't understand a cople things in your solution..
>
> 1)Why do You need another IGP running on tunnel ?
> As soon as You build 135.4.36.0/29 tunn between r5 & r6 - it became part of
> IGRP
> because igrp is running on 135.4.0.0
> Since Armand put mutual igrp/ospf redistr on R6, ospf will know new /29
> network as well.
>
> r5 will learn routes /29 from major class 135.4.0.0 as soon as you have tunn
> /29.
> What the point to have another IGP ???
>
> 2) question to Armand.
> You did redistr connected on r6 and the same time have network
> network 135.4.34.0 0.0.0.7 area 1 under ospf on r6.
> as Eric B. noticed it should not work if you have 12.1(3) or higher
> because:
> In Cisco IOS Software Release 12.1(3) and later, the Type-5 LSAs are no
> longer created for connected networks INCLUDED in the network statements
> under router OSPF.
>
> http://www.cisco.com/warp/public/104/redist-conn.html
>
> I checked it on 12.1.(15) and 12.1(5)T12 - it's true.
>
> What is IOS on r6 ?
>
> 3) And finally:
> You CAN summarize INTRA-area 0 routes towards (i.e. routes originated from
> within area 0)
> towards to area 1 if you put "area 0 range" command on r4.
> Router creates summary to Null automaticaly, and this aggregate will be
> propagated
> to area 1 ONLY, it will NOT appears in any OTHER area of your ospf domain.
>
> 135.4.24.0/27 - this is internal area 0 network "O" isn't it ?
>
> Dmitry
>
>
> -----Original Message-----
> From: William lu [mailto:mailluw@yahoo.com]
> Sent: Monday, August 05, 2002 12:56 AM
> To: Armand D; ccielab@groupstudy.com
> Subject: Re: OSPF into IGRP using Summarization solution
>
>
> Hi Armand,
>
> In order to verify the solution for this issue, I
> built your scenario with the TUNNEL solution and it
> works just fine.
>
> The problem in your configuration is you can not use
> summary address in R6 to summary a OSPF route out of
> OSPF domain. Also you can not use area range to
> summarize 135.4.24.0/27 for area 0 in R4. Too long to
> explain why here.
>
> Solution:
> 1. Build a tunnel between R5 and R6 with any IGP
> protocols other than IGRP and OSPF. Then, send
> 135.4.36.0/29 frm R5 to R6 and redistribute into ospf
> as external route in R6.
> 2. Redistribute 135.4.24.0/27 as connected route with
> route-map (it works in 12.1) into ospf domain.
> 3. At this point, you should have both routes in your
> ospf database as external routes by verifying with ip
> ospf database command.
> 4. Finally, you can use following two commands in R6
> to summarize them into 24bit class routes:
> summary-address 135.4.24.0 255.255.255.0
> summary-address 135.4.36.0 255.255.255.0
> 5. You should see two classful routes in R5's routing
> table as follows:
>
> R 135.4.24.0/29 [120/1] via 150.4.1.2, 00:00:02,
> Tunnel0
> O E2 135.4.24.0/24 [110/20] via 139.11.12.1, 00:00:03,
> Serial0
> O E2 135.4.36.0/24 [110/20] via 139.11.12.1, 00:00:03,
> Serial0
> C 135.4.36.0/27 is directly connected, Loopback10
> R 198.172.20.0/24 [120/2] via 150.4.1.2, 00:00:04,
> Tunnel0
>
> This could be pne of few solutions to make your
> scenario works. It is too long to explain why to can
> not use other ways to work around. Please contact
> Cyscoexpert.com if you need to learn more in detail
> for IGP redistribution. They are the best CCIE
> training center I knew.
>
> Let me know if it works.
>
> William
>
>
> --- Armand D <ciscoworks2001@yahoo.com> wrote:
> > Hello,
> >
> > This is a tough one to get working. I have three
> > routers one running IGRP the other two in OSPF. I
> > have
> > searched the archives for solutions and still can't
> > get this one to work. Router 5 shows all area 1
> > networks /29 with help of "summary-address"
> > command. Router 5 does NOT see any Area 0 /27 routes
> > in routing table.I have tried the "area 0
> > range" command on R4 with no luck. Please look
> > at
> > my configs and tell me what I'm missing here.
> >
> > Any help would be appreciated.
> >
> > R5
> > |
> > |
> > 135.4.56.0/24 IGRP
> > |
> > |
> > R6
> > |
> > |
> > 135.4.36.0/29 OSPF Area 1
> > |
> > |
> > R4
> > |
> > 135.4.24.0/27 OSPF Area 0
> >
> >
> >
> > ====================================
> > hostname R5
> > !
> > ip subnet-zero
> > !
> > interface Loopback0
> > ip address 135.4.5.5 255.255.255.0
> > no ip directed-broadcast
> > !
> > interface Ethernet0/0
> > ip address 135.4.56.5 255.255.255.0
> > no ip directed-broadcast
> > !
> > router igrp 10
> > network 135.4.0.0
> > !
> > ip classless
> > !
> > end
> >
> > ===================================
> > hostname R6
> > !
> > ip subnet-zero
> >
> > interface Loopback0
> > ip address 135.4.6.6 255.255.255.0
> > no ip directed-broadcast
> >
> > interface Loopback200
> > ip address 135.4.66.6 255.255.255.0
> > no ip directed-broadcast
> > ip ospf network point-to-point
> > !
> > interface Serial0/0
> > description to R4
> > ip address 135.4.34.6 255.255.255.248
> > no ip directed-broadcast
> > encapsulation frame-relay
> > ip ospf message-digest-key 2 md5 secure
> > ip ospf network broadcast
> > ip ospf priority 0
> > frame-relay map ip 135.4.34.4 604 broadcast
> > frame-relay lmi-type cisco
> > !
> > interface Ethernet0/1
> > description to R5 IGRP
> > ip address 135.4.56.6 255.255.255.0
> > no ip directed-broadcast
> > !
> > router ospf 1
> > summary-address 135.4.34.0 255.255.255.0
> > redistribute igrp 10 metric 1 subnets
> > network 135.4.6.6 0.0.0.0 area 1
> > network 135.4.34.0 0.0.0.7 area 1
> > network 135.4.36.0 0.0.0.255 area 33
> > area 0 authentication
> > area 1 authentication message-digest
> > area 1 virtual-link 135.4.4.4 message-digest-key 2
> > md5 secure
> > !
> > router igrp 10
> > redistribute connected
> > redistribute ospf 1 metric 1 1 255 255 1
> > network 135.4.0.0
> >
> > ==========================
> >
> > hostname R4
> > !
> > ip subnet-zero
> > !
> > interface Loopback0
> > ip address 135.4.4.4 255.255.255.0
> > ip ospf priority 255
> > !
> > interface Serial0/0
> > no ip address
> > encapsulation frame-relay
> > cdp enable
> > frame-relay lmi-type cisco
> > !
> > interface Serial0/0.1 multipoint
> > ip address 135.4.34.4 255.255.255.248
> > no ip split-horizon
> > ip ospf message-digest-key 2 md5 secure
> > ip ospf network broadcast
> > frame-relay map ip 135.4.34.6 406 broadcast
> > !
> > interface Ethernet0/1
> > description to to R2
> > ip address 135.4.24.4 255.255.255.224
> > ip ospf authentication-key cisco
> > !
> > router ospf 1
> > area 0 authentication
> > area 0 range 135.4.24.0 255.255.255.0 cost 1
> > area 1 authentication message-digest
> > area 1 virtual-link 135.4.6.6 message-digest-key 2
> > md5 secure
> > network 135.4.4.4 0.0.0.0 area 0
> > network 135.4.24.0 0.0.0.31 area 0
> > network 135.4.34.0 0.0.0.7 area 1
> > !
> > end
> >
> >
> >
> >
> >
This archive was generated by hypermail 2.1.4 : Sat Sep 07 2002 - 19:48:17 GMT-3