I copied your configurations in a simple CML lab and the neighbors established just fine. One difference however is that I am using the NXOS 9000v image (closer to a Nexus 3K) as opposed to what seems to be a Nexus 7K image in your virtualized environment.
Can you share the configurations from the production or pre-production lab instead to make sure we are comparing apples to apples? Include the following as well from the N3K:
show ip interface brief | inc up
show ip ospf neighbors
show ip ospf interface brief
show module
show version
P.S: layer3 peer-router is NOT required unless you have two Nexus in vPC. Based on your topology, it seems its a standalone Nexus device for now.
Below are the configurations, outputs and topology from my lab matching yours:
Nexus-1
Nexus-1# show run ospf
!Command: show running-config ospf
!Running configuration last done at: Mon Aug 29 16:32:27 2022
!Time: Mon Aug 29 16:38:53 2022
version 9.3(8) Bios:version
feature ospf
router ospf 1
router-id 192.168.245.1
default-information originate
distance 220
passive-interface default
interface Vlan15
no ip ospf passive-interface
ip router ospf 1 area 0.0.0.0
Nexus-1# show run int e1/1-2
!Command: show running-config interface Ethernet1/1-2
!Running configuration last done at: Mon Aug 29 16:32:27 2022
!Time: Mon Aug 29 16:38:59 2022
version 9.3(8) Bios:version
interface Ethernet1/1
switchport access vlan 15
interface Ethernet1/2
switchport access vlan 15
Nexus-1# show ip int bri | inc up
Vlan15 10.1.15.100 protocol-up/link-up/admin-up
Lo0 192.168.245.7 protocol-up/link-up/admin-up
Nexus-1# show ip ospf neighbors
OSPF Process ID 1 VRF default
Total number of neighbors: 2
Neighbor ID Pri State Up Time Address Interface
192.168.245.5 255 FULL/DR 00:07:38 10.1.15.3 Vlan15
192.168.245.6 1 FULL/DROTHER 00:05:11 10.1.15.4 Vlan15
Nexus-1# show run int vlan 15
!Command: show running-config interface Vlan15
!Running configuration last done at: Mon Aug 29 16:32:27 2022
!Time: Mon Aug 29 16:39:13 2022
version 9.3(8) Bios:version
interface Vlan15
no shutdown
ip address 10.1.15.100/24
no ip ospf passive-interface
ip router ospf 1 area 0.0.0.0
Nexus-1# show run int loo0
!Command: show running-config interface loopback0
!Running configuration last done at: Mon Aug 29 16:32:27 2022
!Time: Mon Aug 29 16:39:15 2022
version 9.3(8) Bios:version
interface loopback0
ip address 192.168.245.7/24
Nexus-1# show cdp neighbors
Capability Codes: R - Router, T - Trans-Bridge, B - Source-Route-Bridge
S - Switch, H - Host, I - IGMP, r - Repeater,
V - VoIP-Phone, D - Remotely-Managed-Device,
s - Supports-STP-Dispute
Device-ID Local Intrfce Hldtme Capability Platform Port ID
Hub-3 Eth1/1 138 R B Gig0/1
Hub-4 Eth1/2 129 R B Gig0/2
Total entries displayed: 2
Hub-3
Hub-3#show run int g0/1
Building configuration...
Current configuration : 153 bytes
!
interface GigabitEthernet0/1
description LAN
ip address 10.1.15.3 255.255.255.0
ip ospf priority 255
duplex auto
speed auto
media-type rj45
end
Hub-3#show run int loo0
Building configuration...
Current configuration : 90 bytes
!
interface Loopback0
description Hubself
ip address 192.168.245.5 255.255.255.255
end
Hub-3#show run | s r o
router ospf 1
passive-interface default
no passive-interface GigabitEthernet0/1
network 10.1.15.0 0.0.0.255 area 0
network 192.168.245.0 0.0.0.255 area 0
default-information originate
distance ospf external 220
Hub-3#show ip int bri | inc up
GigabitEthernet0/1 10.1.15.3 YES manual up up
Loopback0 192.168.245.5 YES manual up up
Hub-3#show ip ospf neig
Hub-3#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
192.168.245.1 1 FULL/BDR 00:00:39 10.1.15.100 GigabitEthernet0/1
192.168.245.6 1 FULL/DROTHER 00:00:37 10.1.15.4 GigabitEthernet0/1
Hub-3#
Hub-4
Hub-4#show run int g0/2
Building configuration...
Current configuration : 131 bytes
!
interface GigabitEthernet0/2
description LAN
ip address 10.1.15.4 255.255.255.0
duplex auto
speed auto
media-type rj45
end
Hub-4#show run int loo0
Building configuration...
Current configuration : 90 bytes
!
interface Loopback0
description Hubself
ip address 192.168.245.6 255.255.255.255
end
Hub-4#show run | s r o
router ospf 1
passive-interface default
no passive-interface GigabitEthernet0/2
network 10.1.15.0 0.0.0.255 area 0
network 192.168.245.0 0.0.0.255 area 0
default-information originate
distance ospf external 220
Hub-4#show ip int bri | inc up
GigabitEthernet0/2 10.1.15.4 YES manual up up
Loopback0 192.168.245.6 YES manual up up
Hub-4#show ip ospf neighbor
Neighbor ID Pri State Dead Time Address Interface
192.168.245.1 1 FULL/BDR 00:00:36 10.1.15.100 GigabitEthernet0/2
192.168.245.5 255 FULL/DR 00:00:32 10.1.15.3 GigabitEthernet0/2
Hub-4#
