From: Erick B. (erickbe@xxxxxxxxx)
Date: Sun Nov 11 2001 - 18:36:13 GMT-3
Hi,
This is normal behavior for IGRP, a classful routing
protocol.
On Router A, the 200.x.x.x/32 network is on a loopback
interface that is being redistributed into IGRP. The
interfaces and networks part of IGRP are 10.x.x.x
which is another network. The 200.x.x.x/32 network is
a /24 in the classful world so gets put into EIGRP as
a /24. If you replace the 200.x.x.x/32 with a
10.x.x.x/32 network then you'll see that the
10.x.x.x/32 isn't put into IGRP because of the FLSM vs
VLSM issue.
Erick
Go Packers!
--- Albert Lu <albert_ccie@yahoo.com> wrote:
> I've tried no auto-summary, rebooted and still it
> keeps doing it.
>
> -----Original Message-----
> From: nobody@groupstudy.com
> [mailto:nobody@groupstudy.com]On Behalf Of
> Ben-Shalom, Omer
> Sent: Sunday, November 11, 2001 11:17 PM
> To: Albert Lu; 'Ccielab (E-mail)'
> Subject: RE: Weird IGRP and EIGRP Redistribution
> Findings!!
>
>
> Other people may correct me but on the surface of it
> you are getting a
> summary route to the classful network 200.0.0.0 , do
> no auto summary and
> check again.
>
> Omer.
>
> -----Original Message-----
> From: Albert Lu [mailto:albert_ccie@yahoo.com]
> Sent: Sun, November 11, 2001 1:13 PM
> To: 'Ccielab (E-mail)'
> Subject: Weird IGRP and EIGRP Redistribution
> Findings!!
>
>
> Hi All,
>
> Ok, I've found something really strange
> redistributing between EIGRP and
> IGRP. From what I know, the FLSM and VLSM
> redistribution will only
> redistribute routes in the VLSM domain that has the
> same subnet length as
> the interface of the router connecting the two
> networks together. For
> instance, if a router that connects IGRP and EIGRP
> together and they both
> have /24 subnet length, then only the /24 networks
> in EIGRP (the VLSM) will
> be redistributed into IGRP.
>
> I've encounterd a scenario with two routers, where
> the border router between
> EIGRP and IGRP has a loopback interface of /32
> belonging to EIGRP. The
> interfaces in EIGRP and IGRP of the border router is
> /24, so I would assume
> that any other network that is not a /24 in EIGRP
> will not be redistributed
> into IGRP.
>
> However, this /32 network is being redistributed
> into IGRP from EIGRP as a
> /24. So does that mean the redistribution of only
> /24 networks only apply to
> networks that are not directly connected to the
> border router?
>
> Does this also apply for OSPF and IGRP(or RIP)
> redistribution?
>
> Take a look at my configs, debugs and routing
> tables. Basically, it's two
> routers with RA being the border router that has
> IGRP and EIGRP running on
> it. RB has only IGRP running on it.
>
> The 200.0.0.2/32 loopback interface belongs to the
> EIGRP process, however
> after the redistribution in IGRP process on the same
> router, it is sent out
> to RB as 200.0.0.0/24.
>
> Please comment and help!! =)
>
> Thanks
>
> Albert
>
>
> RA
> ------
> hostname RA
> !
> ip subnet-zero
> !
> interface Loopback0
> ip address 10.2.17.1 255.255.255.0
> no ip directed-broadcast
> !
> interface Loopback10
> ip address 200.0.0.2 255.255.255.255 <-------*****
> This has a mask of /32
> no ip directed-broadcast
> !
> interface Serial0
> ip address 10.1.1.1 255.255.255.0
> no ip directed-broadcast
> clockrate 64000
> !
> interface Serial1
> ip address 10.2.2.1 255.255.255.0
> no ip directed-broadcast
> clockrate 64000
> !
> router eigrp 50
> passive-interface Loopback10
> network 200.0.0.0
> <-----------******* Network
> 200.0.0.2/32 part of EIGRP, not IGRP
> !
> router igrp 100
> redistribute eigrp 50 metric 1000 100 255 1 1500
> passive-interface Loopback0
> passive-interface Serial0
> network 10.0.0.0
> !
> no ip classless
> !
>
> RC
> -------
> hostname RC
> !
> ip subnet-zero
> !
> interface Loopback0
> ip address 10.2.25.2 255.255.255.0
> !
> interface Serial0
> ip address 10.2.2.2 255.255.255.0
> !
>
> router igrp 100
> redistribute connected
> passive-interface Loopback0
> network 10.0.0.0
> !
> ip classless
> !
>
>
> RA Routing Table
> ----------------
> 04:58:51: IGRP: received update from 10.2.2.2 on
> Serial1
> 04:58:51: subnet 10.2.25.0, metric 8976
> (neighbor 501)
> 04:59:17: IGRP: sending update to 255.255.255.255
> via Serial1 (10.2.2.1)
> 04:59:17: subnet 10.1.1.0, metric=8476
> 04:59:17: subnet 10.2.17.0, metric=501
> 04:59:17: network 200.0.0.0, metric=501
>
> RA#sh ip route
> Codes: C - connected, S - static, I - IGRP, R - RIP,
> M - mobile, B - BGP
> D - EIGRP, EX - EIGRP external, O - OSPF, IA
> - OSPF inter area
> N1 - OSPF NSSA external type 1, N2 - OSPF
> NSSA external type 2
> E1 - OSPF external type 1, E2 - OSPF external
> type 2, E - EGP
> i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS
> level-2, * - candidate
> default
> U - per-user static route, o - ODR
>
> Gateway of last resort is not set
>
> 200.0.0.0/32 is subnetted, 1 subnets
> C 200.0.0.2 is directly connected, Loopback10
> 10.0.0.0/24 is subnetted, 4 subnets
> C 10.2.2.0 is directly connected, Serial1
> C 10.1.1.0 is directly connected, Serial0
> I 10.2.25.0 [100/8976] via 10.2.2.2, 00:00:10,
> Serial1
> C 10.2.17.0 is directly connected, Loopback0
> RA#
>
> RC Routing Table
> ----------------
> 05:01:02: IGRP: sending update to 255.255.255.255
> via Serial0 (10.2.2.2)
> 05:01:02: subnet 10.2.25.0, metric=501
> 05:01:29: IGRP: received update from 10.2.2.1 on
> Serial0
> 05:01:29: subnet 10.1.1.0, metric 10476
> (neighbor 8476)
> 05:01:29: subnet 10.2.17.0, metric 8976
> (neighbor 501)
> 05:01:29: network 200.0.0.0, metric 8976
> (neighbor 501)
> <--------------****** EIGRP 50 redistributed into
> IGRP 100
> RC#
>
> RC#sh ip route
> Codes: C - connected, S - static, I - IGRP, R - RIP,
> M - mobile, B - BGP
> D - EIGRP, EX - EIGRP external, O - OSPF, IA
> - OSPF inter area
> N1 - OSPF NSSA external type 1, N2 - OSPF
> NSSA external type 2
> E1 - OSPF external type 1, E2 - OSPF external
> type 2, E - EGP
> i - IS-IS, L1 - IS-IS level-1, L2 - IS-IS
> level-2, ia - IS-IS inter
> area
> * - candidate default, U - per-user static
> route, o - ODR
> P - periodic downloaded static route
>
> Gateway of last resort is not set
>
> I 200.0.0.0/24 [100/8976] via 10.2.2.1, 00:01:19,
> Serial0
> 10.0.0.0/24 is subnetted, 4 subnets
> I 10.1.1.0 [100/10476] via 10.2.2.1, 00:01:19,
> Serial0
> C 10.2.2.0 is directly connected, Serial0
> C 10.2.25.0 is directly connected, Loopback0
> I 10.2.17.0 [100/8976] via 10.2.2.1, 00:01:19,
> Serial0
> RC#
>
>
>
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