10-19-2021 12:07 PM
Hello all,
I am doing below GRE lab. I am using OSPF for NBMA networks and EIGRP for Tunnel Networks.
But routing table shows both (OSPF/EIGRP) routes for Lan network.
How to solve this?. I have attached the running config for R11 and R31.
R11:
Int Loop 0 :10.1.1.1/24
Int G 0/1 : 172.16.11.1/24
Int Tunnel 100 : 192.168.100.11/24
R31:
Int Loop 0 :10.3.3.3/24
Int G 0/2 : 172.16.31.1/24
Int Tunnel 100 : 192.168.100.31/24
SP:
Int G 0/1 : 172.16.11.2/24
Int G 0/2 : 172.16.31.2/24
R11#traceroute 10.3.3.3
Type escape sequence to abort.
Tracing the route to 10.3.3.3
VRF info: (vrf in name/id, vrf out name/id)
1 172.16.11.2 2 msec 2 msec 2 msec
2 172.16.31.1 3 msec 2 msec *
Solved! Go to Solution.
10-19-2021 02:41 PM
Hi @Cisconew ,
> But routing table shows both (OSPF/EIGRP) routes for Lan network.
I suppose you mean you receive both ospf and eigrp routes for interface Loopback 0, right?
You can go under router ospf and remove the network for the loopback 0 interface. It will then only be received through eigrp.
R11:
router ospf 1
no network 10.1.1.1 0.0.0.0 area 0
R31:
router ospf 1
no network 10.3.3.3.3 0.0.0.0 area 0
Regards,
10-19-2021 12:56 PM
Hello,
post the full running configs (sh run) of all three routers...
10-19-2021 02:15 PM
10-19-2021 01:25 PM - edited 10-19-2021 02:06 PM
Hi,
Is there a chance you're actually asking why R11 is learning 10.3.3.3/32 via OSPF and 10.3.3.0/24 from EIGRP
and also why does R31 learn 10.1.1.1/32 through OSPF and 10.1.1.0/24 from EIGRP?
Or in short, why does OSPF advertise a network that did not exist under interface (loopback configured with /24 while in routing table /32 appears)?
so why the ospf doing this?
I guess it's because The loopback interface is always defined as Stub Network Link. By default, the network type of the loopback is P2P, and the 32-bit mask is used. This is why the route learned by the IP address of the loopback interface is the host route of /32 regardless of how long the mask length is configured.
The implementation is based on RFC2328.
10-19-2021 02:41 PM
Hi @Cisconew ,
> But routing table shows both (OSPF/EIGRP) routes for Lan network.
I suppose you mean you receive both ospf and eigrp routes for interface Loopback 0, right?
You can go under router ospf and remove the network for the loopback 0 interface. It will then only be received through eigrp.
R11:
router ospf 1
no network 10.1.1.1 0.0.0.0 area 0
R31:
router ospf 1
no network 10.3.3.3.3 0.0.0.0 area 0
Regards,
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