[quagga-dev 16630] Weird route introduced when OSPF P2MP configured

[Srinivas K]

I am seeing below strange route added to routing table.

***@plant# show ip ospf route
.........
N 12.0.0.3/32 [11] area: 0.0.0.0
via 12.0.0.2, eth1

Topology :
==========
Router A, B and C connected via eth1. All are quagga running routers

Router-A eth1 12.0.0.3
===================
interface eth1
ip ospf network point-to-multipoint
!
router ospf
router-id 12.0.0.3
network 12.0.0.0/8 area 0
!
end


Router-B eth1 12.0.0.2
===================
interface eth1
ip ospf network point-to-multipoint
!
router ospf
router-id 12.0.0.2
network 12.0.0.0/8 area 0
!
end


Router-C 12.0.0.1
================
interface eth1
ip ospf network point-to-multipoint
!
router ospf
ospf router-id 12.0.0.1
network 12.0.0.0/8 area 0.0.0.0
!
end


Output at router-C
=================

***@plant# show ip ospf route
============ OSPF network routing table ============
N 12.0.0.1/32 [0] area: 0.0.0.0
directly attached to eth1
N 12.0.0.2/32 [10] area: 0.0.0.0
via 12.0.0.2, eth1
N 12.0.0.3/32 [11] area: 0.0.0.0
via 12.0.0.2, eth1


***@plant# show ip ospf database router

OSPF Router with ID (12.0.0.1)


Router Link States (Area 0.0.0.0)

LS age: 14
Options: 0x2 : *|-|-|-|-|-|E|*
LS Flags: 0x3
Flags: 0x0
LS Type: router-LSA
Link State ID: 12.0.0.1
Advertising Router: 12.0.0.1
LS Seq Number: 8000000d
Checksum: 0x3187
Length: 60
Number of Links: 3

Link connected to: Stub Network
(Link ID) Net: 12.0.0.1
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metric: 0

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 12.0.0.2
(Link Data) Router Interface address: 12.0.0.1
Number of TOS metrics: 0
TOS 0 Metric: 10

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 12.0.0.3
(Link Data) Router Interface address: 12.0.0.1
Number of TOS metrics: 0
TOS 0 Metric: 10


LS age: 23
Options: 0x2 : *|-|-|-|-|-|E|*
LS Flags: 0x6
Flags: 0x0
LS Type: router-LSA
Link State ID: 12.0.0.2
Advertising Router: 12.0.0.2
LS Seq Number: 80000009
Checksum: 0xd2f7
Length: 60
Number of Links: 3

Link connected to: Stub Network
(Link ID) Net: 12.0.0.2
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metric: 0

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 12.0.0.1
(Link Data) Router Interface address: 12.0.0.2
Number of TOS metrics: 0
TOS 0 Metric: 1

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 12.0.0.3
(Link Data) Router Interface address: 12.0.0.2
Number of TOS metrics: 0
TOS 0 Metric: 1


LS age: 14
Options: 0x2 : *|-|-|-|-|-|E|*
LS Flags: 0x6
Flags: 0x0
LS Type: router-LSA
Link State ID: 12.0.0.3
Advertising Router: 12.0.0.3
LS Seq Number: 8000000d
Checksum: 0xe2df
Length: 60
Number of Links: 3

Link connected to: Stub Network
(Link ID) Net: 12.0.0.3
(Link Data) Network Mask: 255.255.255.255
Number of TOS metrics: 0
TOS 0 Metric: 0

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 12.0.0.1
(Link Data) Router Interface address: 12.0.0.3
Number of TOS metrics: 0
TOS 0 Metric: 1

Link connected to: another Router (point-to-point)
(Link ID) Neighboring Router ID: 12.0.0.2
(Link Data) Router Interface address: 12.0.0.3
Number of TOS metrics: 0
TOS 0 Metric: 1