Ospf Wrong Neighbor

[feroz syed]

Hello,

i have two OSPF process id both are different but some how ospf start neighbor with different process id. please someone explain how it possible...

R1#sh run | sec router ospf
router ospf 1
router-id 1.1.1.1
network 10.1.1.0 0.0.0.255 area 0
network 10.1.2.0 0.0.0.255 area 0
R1#
R1#
R1#sh ip os ne

Neighbor ID Pri State Dead Time Address Interface
10.1.2.2 0 FULL/ - 00:00:33 10.1.2.2 FastEthernet0/1
11.11.11.11 0 FULL/ - 00:00:36 10.1.1.11 FastEthernet0/0

---------------------------------------------------------------------------

interface FastEthernet0/0
vrf forwarding MPLS
ip address 10.1.2.2 255.255.255.0
ip ospf network point-to-point
speed auto
duplex auto
end

R2#sh run | sec router ospf
router ospf 100 vrf MPLS
redistribute connected subnets
network 10.1.2.0 0.0.0.255 area 0
router ospf 1
router-id 2.2.2.2
network 2.2.2.2 0.0.0.0 area 0
network 10.2.8.2 0.0.0.0 area 0
mpls ldp autoconfig
R2#
R2#sh ip os ne

Neighbor ID Pri State Dead Time Address Interface
8.8.8.8 0 FULL/ - 00:00:38 10.2.8.8 FastEthernet0/1
1.1.1.1 0 FULL/ - 00:00:30 10.1.2.1 FastEthernet0/0

[balaji.bandi]

check where this interface connected respect interface with cdp neighbour ?

[feroz syed]

R1#sh ip os int br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Fa0/1 1 0 10.1.2.1/24 1 P2P 1/1
Fa0/0 1 0 10.1.1.1/24 1 P2P 1/1

R2#sh ip os int br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Lo0 1 0 2.2.2.2/32 1 LOOP 0/0
Fa0/1 1 0 10.2.8.2/24 1 P2P 1/1
Fa0/0 100 0 10.1.2.2/24 1 P2P 1/1

R1#sh cdp neighbors
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,
D - Remote, C - CVTA, M - Two-port Mac Relay

Device ID Local Intrfce Holdtme Capability Platform Port ID
SW-1 Fas 0/0 122 R 7206VXR Fas 0/0
R2 Fas 0/1 160 R 7206VXR Fas 0/0
R3 Fas 1/0 171 R 7206VXR Fas 0/0

--------------------------------------------

R2#sh cdp ne
Capability Codes: R - Router, T - Trans Bridge, B - Source Route Bridge
S - Switch, H - Host, I - IGMP, r - Repeater, P - Phone,
D - Remote, C - CVTA, M - Two-port Mac Relay

Device ID Local Intrfce Holdtme Capability Platform Port ID
R1 Fas 0/0 166 R 7206VXR Fas 0/1
R4 Fas 1/0 177 R 7206VXR Fas 0/0
R8 Fas 0/1 163 R 7206VXR Fas 0/0

[balaji.bandi]

Can you post tthe running config of the interface connected back to back from R1 and R2 ?

how is these connected ?

[feroz syed]

R1#sh run int fa 0/1
Building configuration...

Current configuration : 125 bytes
!
interface FastEthernet0/1
ip address 10.1.2.1 255.255.255.0
ip ospf network point-to-point
speed auto
duplex auto
end

R1#sh ip os int br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Fa0/1 1 0 10.1.2.1/24 1 P2P 1/1
Fa0/0 1 0 10.1.1.1/24 1 P2P 1/1

--------------------------------------------------------------------------

R2#sh ip os int br
Interface PID Area IP Address/Mask Cost State Nbrs F/C
Lo0 1 0 2.2.2.2/32 1 LOOP 0/0
Fa0/1 1 0 10.2.8.2/24 1 P2P 1/1
Fa0/0 100 0 10.1.2.2/24 1 P2P 1/1
R2#sh run int fa 0/0
Building configuration...

Current configuration : 146 bytes
!
interface FastEthernet0/0
vrf forwarding MPLS
ip address 10.1.2.2 255.255.255.0
ip ospf network point-to-point
speed auto
duplex auto
end

[paul driver]

Hello

Note- Two peering ospf rtr CAN have differing PIDs these are only locally significant to the rtr it is applied on

[feroz syed]

You mean Ospf can neighbor with Process ID 1 and ID 100, so only the network range should be same rit ?

[paul driver · Accepted solution]

Hello

---

@feroz syed wrote:

You mean Ospf can neighbor with Process ID 1 and ID 100, so only the network range should be same rit ?

---

yes as long as the area i'd ,network,mtu etc    match they can surely peer with each other