Redistribute EIGRP to OSPF one network not redistributing

[chueymtz]

I went thru and added the following

existing eigrp:

router eigrp 99
network 10.76.0.0 0.0.0.255
network 10.76.2.0 0.0.0.255
network 10.76.10.0 0.0.0.255
network 10.76.200.0 0.0.0.255
network 172.16.0.0
network 192.168.10.0

redistribute ospf 99 metric 10000 10 255 6 1500

added this:

router ospf99
network 10.76.0.0 0.0.0.255 area 0
network 10.76.2.0 0.0.0.255 area 0
network 10.76.10.0 0.0.0.255 area 0
network 10.76.200.0 0.0.0.255 area 0
network 172.16.0.0 0.0.1.255 area 0
network 192.168.10.0 0.0.0.255 area 0

redistribute ospf 99 subnets

When I check the routes all of them show up with EX2 that are being redistributed except for the 172.16.0.0 network so when I remove eigrp I lose that part of the network.

Can someone help with this?

[Giuseppe Larosa]

Hello @chueymtz ,

only routes installed in the IP routing table can be redistributed

check

show ip route 172.16.0.0

and see if the route is present.  And in the case it is present what is the protocol that provides it.

Edit:

you are performing two ways mutual redistribution this is not recommended . IT is better to use single way redistribution in the protocol used in the backbone, the other protocol can create a default route instead of getting route details.

I know that a lot of books show mutual redistribution but in real world we can avoid this most of the times.

You may be in the phase of migration from one IGP to other IGP.

Hope to help

Giuseppe

[chueymtz]

Hello, thanks for the response, yes the route is showing up

9300#sho ip route 172.16.0.0
Routing entry for 172.16.0.0/16, 21 known subnets
Attached (2 connections)
Variably subnetted with 2 masks
Redistributing via eigrp 99, ospf 99
D 172.16.2.0/23 [90/28416] via 10.76.200.2, 1w6d, GigabitEthernet1/0/1
D 172.16.4.0/23 [90/28416] via 10.76.200.4, 1w6d, GigabitEthernet1/0/1
D 172.16.6.0/23 [90/28416] via 10.76.200.6, 1w6d, GigabitEthernet1/0/1
D 172.16.8.0/23 [90/28416] via 10.76.200.8, 1d06h, GigabitEthernet1/0/1
C 172.16.10.0/23 is directly connected, Vlan200
L 172.16.10.1/32 is directly connected, Vlan200
D 172.16.12.0/23
[90/28416] via 10.76.200.12, 1d07h, GigabitEthernet1/0/1
D 172.16.14.0/23
[90/28416] via 10.76.200.14, 1w6d, GigabitEthernet1/0/1
D 172.16.16.0/23
[90/28416] via 10.76.200.16, 1d06h, GigabitEthernet1/0/1
D 172.16.18.0/23
[90/28416] via 10.76.200.18, 1w0d, GigabitEthernet1/0/1
D 172.16.22.0/23
[90/28416] via 10.76.200.22, 01:40:26, GigabitEthernet1/0/1
D 172.16.24.0/23
[90/28416] via 10.76.200.24, 2d01h, GigabitEthernet1/0/1
D 172.16.28.0/23
[90/28416] via 10.76.200.28, 1w6d, GigabitEthernet1/0/1
D 172.16.32.0/23
[90/28416] via 10.76.200.32, 1w6d, GigabitEthernet1/0/1
D 172.16.34.0/23
[90/28416] via 10.76.200.34, 1w3d, GigabitEthernet1/0/1
D 172.16.36.0/23
[90/28416] via 10.76.200.36, 1w6d, GigabitEthernet1/0/1
D 172.16.38.0/23
[90/28416] via 10.76.200.38, 1w6d, GigabitEthernet1/0/1
D 172.16.40.0/23
[90/28416] via 10.76.200.40, 1d06h, GigabitEthernet1/0/1
D 172.16.42.0/23
[90/28416] via 10.76.200.42, 00:32:52, GigabitEthernet1/0/1
D 172.16.44.0/23
[90/28416] via 10.76.200.44, 1w6d, GigabitEthernet1/0/1
D 172.16.50.0/23

This is the first time i'm trying a redistribute, when you say way mutual distribution, should i only include the redistribution on the eigrp 99 part?

[Giuseppe Larosa]

Hello @chueymtz ,

we can see that under major network 172.16.0.0/16 in the routing table there are several prefixes /23 starting from 172.16.2.0/23.

to be noted 172.16.0.0/23 does not exist as an EIGRP route

Redistributing via eigrp 99, ospf 99
D 172.16.2.0/23 [90/28416] via 10.76.200.2, 1w6d, GigabitEthernet1/0/1
D 172.16.4.0/23 [90/28416] via 10.76.200.4, 1w6d, GigabitEthernet1/0/1
D 172.16.6.0/23 [90/28416] via 10.76.200.6, 1w6d, GigabitEthernet1/0/1
D 172.16.8.0/23 [90/28416] via 10.76.200.8, 1d06h, GigabitEthernet1

As a result of this and for the fact that you use the subnets keyword under router ospf to redistribute EIGRP in OSPF no LSA type 5 for prefix 172.16.0.0/16 or 172.16.0.0/23 are present.

you can check this by yourself using

show ip ospf database external

you should see entries for all the 172.16.2.0/23 , 172.16.4.0/23 and so on.

>> when you say way mutual distribution, should i only include the redistribution on the eigrp 99 part?

I cannot say for sure that you can avoid to redistribute OSPF into EIGRP, but you can consider this.

if OSPF is in the backbone you can use an ip eigrp summary-address under appropriate interface to send out even a default route or one or more supernets like 10.0.0.0/8 , 172.16.0.0/16 and so on ( each of them requires a separate ip eigrp 99 summary-address command).

Are you in the process to migrate from EIGRP to OSPF ?

And yes the prefix can also be present in the routing table as connected and it will be redistributed from EIGRP into OSPF you can check this using

show ip ospf database external 172.16.10.0

in IPv4 we don't need to use the include-connected as far as I know the command is present in IPv6 redistribution.

Good note @David Ruess 

Hope to help

Giuseppe

[David Ruess]

In addition to what @Giuseppe Larosa said when you redistribute routes on the local router even if the subnets belong to a certain routing protocol they are still directly connected and show up as that way in the routing table. Some protoocls allow you to use the "include-connected" keyword but that may be only for IPv6. If the route is on the device youre using to perform redistribution you may need to also redistribute connected routes.

-David

[MHM Cisco World]

router eirgp 99
redistribute ospf 99 metric 10000 10 255 6 1500 route-map <excluded any prefix add directly under eigrp>

router ospf 99 
redistribute eigrp 99 <excluded any prefix directly add under ospf>

do this and you routing will be OK 

MHM
 

[paul driver]

Hello
You OP doesn't seem correct, you have both routing process with the same network statements, if you wish to redistribute in either routing domain then you do not need to add network statements also.

If you do that and the network prefix is originating from the same rtr as the redistribution, the network statement will take precedence over redistribution

[chueymtz]

Update:

I've opened a ticket with Cisco and this is what we came up with

router ospf 99
network 10.76.0.0 0.0.255.255 area 0
network 10.78.0.0 0.0.255.255 area 0
network 172.16.0.0 0.0.255.255 area 0
network 192.168.0.0 0.0.255.255 area 0

The issue now is that anything that is on the 10.76.0.0 network is unable to get online, the rest is working correctly as 172.16.x.x does not have internet anyways. This is my current acl that was working with eigrp and works with eigrp if i remove ospf:

!
ip access-list standard 50
10 permit 192.168.0.0 0.0.255.255
20 permit 10.76.0.0 0.0.255.255
30 permit 10.78.0.0 0.0.255.255
ip access-list extended 101
10 deny ip any 172.16.0.0 0.0.255.255
20 permit ip any any
ip access-list extended 102
10 permit ip any 172.16.0.0 0.0.255.255
20 permit ip any 10.243.x.0 0.0.1.255
30 permit ip any 10.233.x.0 0.0.1.255

[MHM Cisco World]

Sorry what is this ACL? Can you more elaborate

MHM

[chueymtz]

It's posted:

ACL:

ip access-list standard 50
10 permit 192.168.0.0 0.0.255.255
20 permit 10.76.0.0 0.0.255.255
30 permit 10.78.0.0 0.0.255.255
ip access-list extended 101
10 deny ip any 172.16.0.0 0.0.255.255
20 permit ip any any
ip access-list extended 102
10 permit ip any 172.16.0.0 0.0.255.255
20 permit ip any 10.243.x.0 0.0.1.255
30 permit ip any 10.233.x.0 0.0.1.255

[MHM Cisco World]

For what this ACL use for 

NAT 

Or route-map for redistribute 

MHM

[MHM Cisco World]

R1#show running-config
Building configuration...

Current configuration : 1734 bytes
!
! Last configuration change at 09:35:12 UTC Sun Sep 29 2024
!
version 15.2
service timestamps debug datetime msec
service timestamps log datetime msec
!
hostname R1
!
boot-start-marker
boot-end-marker
!
!
!
no aaa new-model
no ip icmp rate-limit unreachable
ip cef
!
!
!
!
!
!
no ip domain lookup
no ipv6 cef
!
!
multilink bundle-name authenticated
!
!
!
!
!
!
!
!
!
ip tcp synwait-time 5
!
!
!
!
!
!
!
!
!
!
!
!
interface Loopback0
no ip address
!
interface Loopback1
ip address 1.1.1.1 255.255.255.255
!
interface Loopback11
ip address 11.11.11.11 255.255.255.255
!
interface FastEthernet0/0
ip address 100.0.0.1 255.255.255.0
duplex full
!
interface FastEthernet1/0
no ip address
shutdown
speed auto
duplex auto
!
interface FastEthernet1/1
ip address 200.0.0.1 255.255.255.0
speed auto
duplex auto
!
interface FastEthernet2/0
no ip address
shutdown
speed auto
duplex auto
!
interface FastEthernet2/1
no ip address
shutdown
speed auto
duplex auto
!
!
router eigrp 200
network 200.0.0.0
redistribute ospf 100 metric 1000 100 255 100 1500 route-map NO-Local
redistribute connected
!
router ospf 100
redistribute connected subnets
redistribute eigrp 200 subnets route-map NO-Local
network 100.0.0.0 0.0.0.255 area 0
!
ip forward-protocol nd
!
!
no ip http server
no ip http secure-server
!
!
ip prefix-list 1.1.1.1 seq 5 permit 1.1.1.1/32
ip prefix-list 1.1.1.1 seq 10 permit 11.11.11.11/32
!
route-map NO-Local deny 10
match ip address prefix-list 1.1.1.1
!
route-map NO-Local permit 20
!
!
!
control-plane
!
!
line con 0
exec-timeout 0 0
privilege level 15
logging synchronous
stopbits 1
line aux 0
exec-timeout 0 0
privilege level 15
logging synchronous
stopbits 1
line vty 0 4
login
!
!
end

[MHM Cisco World]

So the Q, why you run both eigrp and ospf ?
in my lab I run both since there are two neighbour each one run different igp, one run ospf and other eigrp 

MHM

[chueymtz]

Hello,

I have to as we have 23 other routers that are running EIGRP and I am in the process of moving to ospf so I can’t just remove eigrp.

[MHM Cisco World]

Ok' friend to access any IP in internet you need default route and as I mentioned before eigrp can redistrubte defualt with static but ospf you need defualt information originate.

MHM