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 ,

what are the purposes of the posted ACLs ?

access-list 50 is a standard ACL

Access-list 101 and 102 are extended ACLs but they don't look as ACL used for NAT because the subnets appear in the destination field.

>> 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:

so my guess is that ACL 50 might be used by NAT  or for performing PBR.

Access-list 101 and 102 look like ACLs appiled inbound on interfaces towards the internet.

ACL 101 applied inbound on an interface to Internet. ACL 102 applied may be applied inbound to some other interface.

Also it is important to know what devices are involved, what devices do NAT, if there are Stateful Firewalls before  the internet access for example the issue can be that traffic coming the FW when EIGRP is enabled hits interface A and traffic coming to the FW when OSPF is enabled hits interface B.

The FW needs security rules to accept traffic on interface A and on interface B, the rules for interface B can be different and ths can cause the issue.

I'm doing just an example.

You should provide more details and a network diagram to get better help. The issue can be caused by another device and it not related to moving from EIGRP to OSPF.

Edit:

starting from of one the affected subnets like 10.76.2.0/23  I would suggest the following:

traceroute to 8.8.8.8 when using EIGRP and ping to 8.8.8.8 works

then traceroute to 8.8.8.8 from subnet 10.76.2.0/23 when using OSPF

then you compare the IP next-hops in the traceroute and look for any difference in the  first IP hops

Hope to help

Giuseppe

[chueymtz]

Here's what i get when I enable eigrp and remove ospf, internet works how it's supposed to. I did nothing else other than remove ospf and paste back in original eigrp rule

1 <1 ms <1 ms <1 ms 10.76.10.1
2 3 ms 3 ms 3 ms 10.76.200.40
3 2 ms 2 ms 2 ms 10.76.200.2
4 3 ms 2 ms 2 ms 10.76.2.1xx
5 3 ms 3 ms 2 ms 4.36.xx.xxx
6 26 ms 7 ms 7 ms et-4-0-xx-x.bar4.xxxxx.Level3.net [4.36.xx.xxx]
7 * * * Request timed out.
8 13 ms 13 ms 13 ms 142.250.xxx.xx
9 13 ms 12 ms 13 ms 142.251.xxx.xxx
10 13 ms 18 ms 12 ms 74.125.xx.xxx
11 13 ms 12 ms 12 ms dns.google [8.8.8.8]

[chueymtz]

And this is what I get when I put ospf back in and remove eigrp

Tracing route to dns.google [8.8.8.8]
over a maximum of 30 hops:

1 <1 ms * 1 ms 10.76.10.1
2 1 ms * 1 ms 10.76.10.1
3 10.76.10.1 reports: Destination host unreachable.

[MHM Cisco World]

10.76.10.1 <<- check in this node.

Different between ospf and eigrp is 

Eigrp redistrubte defualt route as static route' i.e. redistrubte static cover both static abd defualt 

Ospf not redistrubte defualt  route via redistrubte static and hence you need cobfig defualt originate 

MHM

[Giuseppe Larosa]

Hello @chueymtz ,

the node with IP 10.76.10.1 is the one where you have to focus on.

As suggested you have to also to verify if a default route exist in OSPF domain on border routers connected to the internet if they speak OSPF on internal interface you need to use

router ospf 10

default-information originate

if you have more then one border routers you can use a variation like the following:

to check that the local default comes from the ISP router.

access-list 22 permit host 22.x.y.z

ip prefix-list ONLY-DEFAULT seq 1 pemit 0.0.0.0/0

route-map CHECK-DEFAULT permit 10

match address prefix ONLY-DEFAULT

match ip next-hop 22

set metric 50

set metric-type 1

router ospf 10

default-information originate CHECK-DEFAULT

Howeveer , if there are some prefixes that when OSPF is enabled  can reach the internet this points not to a routing problem.

For start you can check the node with IP 10.76.10.1

check

show ip route 0.0.0.0 with EIGRP enabled

check show ip route 0.0.0.0 with OSPF enabled

Hope to help

Giuseppe

[chueymtz · Accepted solution]

 I figured it out, my gateway of last resort was not set when I converted to ospf, once I set that per my eigrp which was 10.76.x.x it worked.

[MHM Cisco World]

Glad issue is solved

Have a nice day 

MHM