OSPFv2 and OSPFv3 verification of area 1.

In this area, two interesting things are happing. There is a multiaccess segment with four attached routers and there is some summarization going on into area 0 (configured on R12).

Let's start with the verification of the multiaccess segment and then move on towards the summarization.



scenario


R15 is configured to be the DR and S1 is configured to be the BDR. Let's verify this by examining the following output on R6:

 
play@MX80:R6> show ospf neighbor extensive
Address          Interface              State     ID               Pri  Dead
2.0.0.122        ge-1/1/3.2000          2Way      45.0.0.1           0    38
  Area 0.0.0.1, opt 0x12, DR 2.0.0.121, BDR 2.0.0.123
  Up 2w0d 02:42:50
   Topology default (ID 0) -> Bidirectional
2.0.0.121        ge-1/1/3.2000          Full      1.1.1.15         200    39
  Area 0.0.0.1, opt 0x42, DR 2.0.0.121, BDR 2.0.0.123
  Up 1w4d 03:40:20, adjacent 1w4d 03:40:20
   Topology default (ID 0) -> Bidirectional
2.0.0.123        ge-1/1/3.2000          Full      145.0.0.1        175    39
  Area 0.0.0.1, opt 0x52, DR 2.0.0.121, BDR 2.0.0.123
  Up 2w0d 02:42:50, adjacent 1w4d 03:40:15
   Topology default (ID 0) -> Bidirectional

play@MX80:R6> show ospf3 neighbor extensive
ID               Interface              State     Pri   Dead
145.0.0.1        ge-1/1/3.2000          Full      175     34
  Neighbor-address fe80::5e5e:abff:fe0d:ee60
  Area 0.0.0.1, opt 0x13, OSPF3-Intf-Index 3
  DR-ID 1.1.1.15, BDR-ID 145.0.0.1
  Up 20:33:01, adjacent 20:33:01
45.0.0.1         ge-1/1/3.2000          2Way        0     32
  Neighbor-address fe80::2e21:72ff:fea3:8041
  Area 0.0.0.1, opt 0x13, OSPF3-Intf-Index 2
  DR-ID 1.1.1.15, BDR-ID 145.0.0.1
  Up 20:33:48
1.1.1.15         ge-1/1/3.2000          Full      200     32
  Neighbor-address fe80::8ae0:f307:d055:f8f6
  Area 0.0.0.1, opt 0x13, OSPF3-Intf-Index 4
  DR-ID 1.1.1.15, BDR-ID 145.0.0.1
  Up 20:33:48, adjacent 20:33:48
                

In OSPFv2, we can see that the DR and BDR have their interface IP address listed in every neighbor relationship. When we check the neighbor relationships with R15 and S1, we can see that their interface IP addresses correspond to the DR and BDR.

In OSPFv3, spotting the DR and BDR is a little more obvious as their router ID's are listed in the output.

Let's move over to R15 and verify that the DR is representing the multiaccess segment to the rest of the network. The following is the verification of OSPFv2:

 
play@MX480-TEST:R15> show ospf database advertising-router self network extensive

    OSPF database, Area 0.0.0.1
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
Network *2.0.0.121        1.1.1.15         0x80000148   550  0x22 0xd9ad  40
  mask 255.255.255.248
  attached router 1.1.1.15
  attached router 1.1.1.6
  attached router 145.0.0.1
  attached router 45.0.0.1
  Topology default (ID 0)
    Type: Transit, Node ID: 45.0.0.1
      Metric: 0, Bidirectional
    Type: Transit, Node ID: 145.0.0.1
      Metric: 0, Bidirectional
    Type: Transit, Node ID: 1.1.1.6
      Metric: 0, Bidirectional
    Type: Transit, Node ID: 1.1.1.15
      Metric: 0, Bidirectional
  Gen timer 00:40:49
  Aging timer 00:50:49
  Installed 00:09:10 ago, expires in 00:50:50, sent 00:09:08 ago
  Last changed 1w4d 03:47:34 ago, Change count: 4, Ours
                

This is rather self-explanatory. The prefix of the segment and all the connected routers are listed in the Network-LSA.

OSPFv3 will be a little different as the prefix information was moved from the Network-LSA into the Intra-Area-Prefix-LSA. Let's check the Network-LSA:

 
play@MX480-TEST:R15> show ospf3 database advertising-router self network extensive

    OSPF3 database, Area 0.0.0.1
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
Network    *0.0.0.4          1.1.1.15         0x8000001c  2014  0x3bb8  40
  Options 0x33
  Attached router 1.1.1.15
  Attached router 145.0.0.1
  Attached router 1.1.1.6
  Attached router 45.0.0.1
  Type: Transit, Node ID: 45.0.0.1, Metric: 0, Bidirectional
  Type: Transit, Node ID: 1.1.1.6, Metric: 0, Bidirectional
  Type: Transit, Node ID: 145.0.0.1, Metric: 0, Bidirectional
  Type: Transit, Node ID: 1.1.1.15, Metric: 0, Bidirectional
  Gen timer 00:16:26
  Aging timer 00:26:26
  Installed 00:33:34 ago, expires in 00:26:26, sent 00:33:32 ago
  Last changed 20:43:27 ago, Change count: 3, Ours
                

We see that R15, the DR, is advertising the Network-LSA. We also see that in OSPFv3, the LSA contains information about what other routers are connected to the segment as well.

To obtain the prefix information, we have to examine the Inter-Area-Prefix-LSA;

 
play@MX480-TEST:R15> show ospf3 database advertising-router self intra-area-prefix extensive lsa-id 0.0.0.5

    OSPF3 database, Area 0.0.0.1
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
IntraArPfx *0.0.0.5          1.1.1.15         0x8000001c  2693  0xe850  44
  Ref-lsa-type Network, Ref-lsa-id 0.0.0.4, Ref-router-id 1.1.1.15
  Prefix-count 1
  Prefix 2001:2:120::/64
    Prefix-options 0x0, Metric 0
  Gen timer 00:05:07
  Aging timer 00:15:07
  Installed 00:44:53 ago, expires in 00:15:07, sent 00:44:51 ago
  Last changed 20:47:47 ago, Change count: 1, Ours
                

Let's move on and check the summarization. R15 is advertising additional prefixes. These additional prefixes were configured on the loopback. We can confirm the advertisement of these prefixes by examining the OSPFv2 Router-LSA and the OSPFv3 Inter-Area-Prefix-LSA.

 
play@MX480-TEST:R15> show ospf database advertising-router self router detail

    OSPF database, Area 0.0.0.1
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
Router  *1.1.1.15         1.1.1.15         0x800003b8   385  0x22 0x62db 144
  bits 0x0, link count 10
  id 1.1.1.14, data 16.0.0.17, Type PointToPoint (1)
    Topology count: 0, Default metric: 1
  id 16.0.0.16, data 255.255.255.252, Type Stub (3)
    Topology count: 0, Default metric: 1
  id 190.0.0.1, data 19.0.0.2, Type PointToPoint (1)
    Topology count: 0, Default metric: 1
  id 19.0.0.0, data 255.255.255.252, Type Stub (3)
    Topology count: 0, Default metric: 1
  id 1.1.1.15, data 255.255.255.255, Type Stub (3)
    Topology count: 0, Default metric: 0
  id 80.0.2.0, data 255.255.255.0, Type Stub (3)
    Topology count: 0, Default metric: 0
  id 80.0.3.0, data 255.255.255.0, Type Stub (3)
    Topology count: 0, Default metric: 0
  id 80.0.1.1, data 255.255.255.255, Type Stub (3)
    Topology count: 0, Default metric: 0
  id 80.0.0.0, data 255.255.255.0, Type Stub (3)
    Topology count: 0, Default metric: 0
  id 2.0.0.121, data 2.0.0.121, Type Transit (2)
    Topology count: 0, Default metric: 1
  Topology default (ID 0)
    Type: Transit, Node ID: 2.0.0.121
      Metric: 1, Bidirectional
    Type: PointToPoint, Node ID: 190.0.0.1
      Metric: 1, Bidirectional
    Type: PointToPoint, Node ID: 1.1.1.14
      Metric: 1, Bidirectional

play@MX480-TEST:R15> show ospf3 database advertising-router self intra-area-prefix detail lsa-id 0.0.0.1

    OSPF3 database, Area 0.0.0.1
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
IntraArPfx *0.0.0.1          1.1.1.15         0x800000c6   397  0x21db 112
  Ref-lsa-type Router, Ref-lsa-id 0.0.0.0, Ref-router-id 1.1.1.15
  Prefix-count 6
  Prefix 2001:16:17::/64
    Prefix-options 0x0, Metric 1
  Prefix 2001::15/128
    Prefix-options 0x2, Metric 0
  Prefix 2001:80::/64
    Prefix-options 0x0, Metric 0
  Prefix 2001:80:1::/64
    Prefix-options 0x0, Metric 0
  Prefix 2001:80:2::/64
    Prefix-options 0x0, Metric 0
  Prefix 2001:80:3::/64
    Prefix-options 0x0, Metric 0
                

Since the output was rather large, all additional subnets configured under the loopback interface are shown in red.

Without summarization, R12 would have produced 4 Summary-LSAs in OSPFv2 and 4 Inter-Area-Prefix-LSAs in OSPFv3. Instead, in both OSPFv2 and OSPFv3, only 1 address is advertised into area 0.

 
play@MX480-TEST:R12> show ospf database advertising-router self area 0.0.0.0 extensive netsummary lsa-id 80.0.0.0

    OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
Summary *80.0.0.0         1.1.1.12         0x8000029b  2057  0x22 0xde63  28
  mask 255.255.252.0
  Topology default (ID 0) -> Metric: 2
  Gen timer 00:15:43
  Aging timer 00:25:43
  Installed 00:34:17 ago, expires in 00:25:43, sent 00:34:15 ago
  Last changed 21:03:48 ago, Change count: 10, Ours

play@MX480-TEST:R12> show ospf3 database advertising-router self area 0.0.0.0 extensive inter-area-prefix lsa-id 0.0.0.15

    OSPF3 database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
InterArPfx *0.0.0.15         1.1.1.12         0x800000ab  1121  0x2f6d  36
  Prefix 2001:80::/46
  Prefix-options 0x0, Metric 2
  Gen timer 00:31:19
  Aging timer 00:41:19
  Installed 00:18:41 ago, expires in 00:41:19, sent 00:18:39 ago
  Last changed 5d 19:59:05 ago, Change count: 2, Ours
                

That's all.

17-10-2014