OSPFv2 and OSPFv3 verification of area 0.

The configuration was about establishing adjacencies and having R11 redistribute a static route into OSPF.



scenario


In verifying the things we configured, let’s start out by checking the adjacencies on R13.

 
play@MX480-TEST:R13> show ospf neighbor extensive
Address          Interface              State     ID               Pri  Dead
16.0.0.1         ge-0/1/0.3028          Full      1.1.1.12         128    32
  Area 0.0.0.0, opt 0x42, DR 0.0.0.0, BDR 0.0.0.0
  Up 00:00:08, adjacent 00:00:08
  Topology default (ID 0) -> Bidirectional
16.0.0.5         ge-0/1/0.3029          Full      1.1.1.11         128    32
  Area 0.0.0.0, opt 0x42, DR 0.0.0.0, BDR 0.0.0.0
  Up 00:00:08, adjacent 00:00:08
  Topology default (ID 0) -> Bidirectional

play@MX480-TEST:R13> show ospf3 neighbor extensive
ID               Interface              State     Pri   Dead
1.1.1.12         ge-0/1/0.3028          Full      128     39
  Neighbor-address fe80::8ae0:f30b:d455:f800
  Area 0.0.0.0, opt 0x13, OSPF3-Intf-Index 2
  DR-ID 0.0.0.0, BDR-ID 0.0.0.0
  Up 00:00:09, adjacent 00:00:04
1.1.1.11         ge-0/1/0.3029          Full      128     31
  Neighbor-address fe80::8ae0:f30b:d555:f800
  Area 0.0.0.0, opt 0x13, OSPF3-Intf-Index 1
  DR-ID 0.0.0.0, BDR-ID 0.0.0.0
  Up 00:00:09, adjacent 00:00:09
                

In the output above, we can see that both the commands and the output are nearly identical. In both the OSPFv2 and OSPFv3 output, we can see that we have establish two adjacencies. OSPFv2 uses the neighboring IPv4 address to establish an adjacency. Since OSPFv3 uses the link-local address, the link-local address is shown in the ‘show ospf3 neighbor’ output. Also, since the links in this area are configured as ‘point-to-point’ links, the DR and BDR in both OSPFv2 and OSPFv3 are 0.0.0.0.

Let’s have a look at R13’s contribution to the LSDB. We haven’t configured any redistribution on this router, so the only addition to the LSDB should be the links of R13:

                 
play@MX480-TEST:R13> show ospf database advertising-router self

    OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
Router  *1.1.1.13         1.1.1.13         0x800003d7  1424  0x22 0x8104  84

play@MX480-TEST:R13> show ospf3 database advertising-router self

    OSPF3 database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
Router     *0.0.0.0          1.1.1.13         0x800000d2  1418  0x796d  56
IntraArPfx *0.0.0.1          1.1.1.13         0x800000cb   488  0xd971  76

    OSPF3 Link-Local database, interface ge-0/1/0.3028 Area 0.0.0.0
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
Link       *0.0.0.2          1.1.1.13         0x800000ad  1355  0x6d85  56

    OSPF3 Link-Local database, interface ge-0/1/0.3029 Area 0.0.0.0
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
Link       *0.0.0.3          1.1.1.13         0x800000ac  2105  0x9e4   56
                

We can see that in OSPFv2, the only addition is the Router-LSA. In OSPFv3, the output shows that R13 has four additions to make to the LSDB.

Let's examine the OSPFv2's Router-LSA first:

                   
play@MX480-TEST:R13> show ospf database advertising-router self detail

    OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
Router  *1.1.1.13         1.1.1.13         0x800003d7  2061  0x22 0x8104  84
  bits 0x0, link count 5
  id 1.1.1.12, data 16.0.0.2, Type PointToPoint (1)
    Topology count: 0, Default metric: 1
  id 16.0.0.0, data 255.255.255.252, Type Stub (3)
    Topology count: 0, Default metric: 1
  id 1.1.1.11, data 16.0.0.6, Type PointToPoint (1)
    Topology count: 0, Default metric: 1
  id 16.0.0.4, data 255.255.255.252, Type Stub (3)
    Topology count: 0, Default metric: 1
  id 1.1.1.13, data 255.255.255.255, Type Stub (3)
    Topology count: 0, Default metric: 0
  Topology default (ID 0)
    Type: PointToPoint, Node ID: 1.1.1.11
      Metric: 1, Bidirectional
    Type: PointToPoint, Node ID: 1.1.1.12
      Metric: 1, Bidirectional
                

The output is showing us the links R13 has together with the cost and the prefix information.

In OSPFv3, things are slightly different. Instead of advertising one Router-LSA, we saw that R13 was advertising 4 LSAs. These were the Router-LSA, the Intra-Area-Prefix-LSA and 2 Link-LSAs. Let's examine these LSAs one by one in more detail.

The following is the Router LSA:

                 
play@MX480-TEST:R13> show ospf3 database advertising-router self detail router

    OSPF3 database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
Router     *0.0.0.0          1.1.1.13         0x800000d3   340  0x776e  56
  bits 0x0, Options 0x33
  Type PointToPoint (1), Metric 1
      Loc-If-Id 2, Nbr-If-Id 2, Nbr-Rtr-Id 1.1.1.12
  Type PointToPoint (1), Metric 1
      Loc-If-Id 3, Nbr-If-Id 1, Nbr-Rtr-Id 1.1.1.11
  Type: PointToPoint, Node ID: 1.1.1.11, Metric: 1, Bidirectional
  Type: PointToPoint, Node ID: 1.1.1.12, Metric: 1, Bidirectional
                

As you can see, this LSA is deprived of any routing information. The prefixes that R13 is advertising, are shared in the Link-LSA and the Intra-Area-Prefix-LSA. Let's look at the Intra-Area-Prefix-LSA next:

                 
play@MX480-TEST:R13> show ospf3 database advertising-router self detail intra-area-prefix

    OSPF3 database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
IntraArPfx *0.0.0.1          1.1.1.13         0x800000cb  2040  0xd971  76
  Ref-lsa-type Router, Ref-lsa-id 0.0.0.0, Ref-router-id 1.1.1.13
  Prefix-count 3
  Prefix 2001:16:1::/64
    Prefix-options 0x0, Metric 1
  Prefix 2001:16:5::/64
    Prefix-options 0x0, Metric 1
  Prefix 2001::13/128
    Prefix-options 0x2, Metric 0
                

Here we can see the different links together with the prefixes and costs that R13 is sharing with the rest of the area. Of course, the information is shared with the entire OSPFv3 AS and not just the area. The prefixes will be advertised to other areas by means of the Inter-Area-Prefix-LSAs as soon as they hit an ABR. The following is a display showing that R12 (the ABR between area 0 and area 1) is flooding R13's loopback IPv6 address in the form of an Inter-Area-Prefix-LSA:

                    
play@MX480-TEST:R12> show ospf3 database advertising-router self area 0.0.0.1 inter-area-prefix extensive lsa-id 0.0.0.5

    OSPF3 database, Area 0.0.0.1
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
InterArPfx *0.0.0.5          1.1.1.12         0x800000a9  1503  0xcaf1  44
  Prefix 2001::13/128
  Prefix-options 0x0, Metric 1
  Gen timer 00:24:57
  Aging timer 00:34:57
  Installed 00:25:03 ago, expires in 00:34:57, sent 00:25:01 ago
  Last changed 01:03:48 ago, Change count: 2, Ours
                

The last two LSAs that R13 is sharing were the Link-LSA's:

                 
play@MX480-TEST:R13> show ospf3 database advertising-router self detail link

    OSPF3 Link-Local database, interface ge-0/1/0.3028 Area 0.0.0.0
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
Link       *0.0.0.2          1.1.1.13         0x800000ae   315  0x6b86  56
  fe80::8ae0:f30b:d455:f852
  Options 0x33, Priority 128
  Prefix-count 1
  Prefix 2001:16:1::/64 Prefix-options 0x0

    OSPF3 Link-Local database, interface ge-0/1/0.3029 Area 0.0.0.0
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
Link       *0.0.0.3          1.1.1.13         0x800000ad  1737  0x7e5   56
  fe80::8ae0:f30b:d555:f852
  Options 0x33, Priority 128
  Prefix-count 1
  Prefix 2001:16:5::/64 Prefix-options 0x0
                

These LSAs are flooded only on the link. This means that the top Link-LSA is flooded only to R12 and the bottom LSA is flooded only to R11. The Link-LSA provides the routers link-local address and informs the other routers of the IPv6 prefixes associated with the link.

Let's move over to R11 and verify the redistribution of the static route into OSPFv2 and OSPFv3;

                 
play@MX480-TEST:R11> show ospf database advertising-router self external extensive
    OSPF AS SCOPE link state database
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
Extern  *212.0.0.0        1.1.1.11         0x8000017b  2492  0x22 0xdf74  36
  mask 255.255.255.0
  Topology default (ID 0)
    Type: 2, Metric: 0, Fwd addr: 0.0.0.0, Tag: 0.0.0.0
  Gen timer 00:08:28
  Aging timer 00:18:28
  Installed 00:41:32 ago, expires in 00:18:28, sent 00:41:30 ago
  Last changed 1w4d 01:53:54 ago, Change count: 2, Ours

play@MX480-TEST:R11> show ospf3 database advertising-router self external extensive
    OSPF3 AS SCOPE link state database
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
Extern     *0.0.0.1          1.1.1.11         0x80000019   802  0x77fc  36
  Prefix 2001:212::/64
  Prefix-options 0x0, Metric 0, Type 2,
  Gen timer 00:36:37
  Aging timer 00:46:37
  Installed 00:13:22 ago, expires in 00:46:38, sent 00:13:20 ago
  Last changed 19:42:54 ago, Change count: 1, Ours
                

The above output shows us that both routers are advertising External-LSAs. This means that both routers are AS boundary routers.

In OSPFv2, there will be an ASBR-Summary-LSA to convey the location of the ASBR to other area. In OSPFv3, we will have to look for an Inter-Area-Router-LSA. Let's hop over to R12 and do just that:

                 
play@MX480-TEST:R12> show ospf database advertising-router self asbrsummary area 0.0.0.1 extensive

    OSPF database, Area 0.0.0.1
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len
ASBRSum *1.1.1.11         1.1.1.12         0x8000017a  1957  0x22 0xa6fb  28
  mask 0.0.0.0
  Topology default (ID 0) -> Metric: 2
  Gen timer 00:17:14
  Aging timer 00:27:23
  Installed 00:32:37 ago, expires in 00:27:23, sent 00:32:35 ago
  Last changed 01:20:44 ago, Change count: 3, Ours


play@MX480-TEST:R12> show ospf3 database advertising-router self inter-area-router extensive area 0.0.0.1

    OSPF3 database, Area 0.0.0.1
 Type       ID               Adv Rtr           Seq         Age  Cksum  Len
InterArRtr *0.0.0.4          1.1.1.12         0x80000019  1857  0xeedc  32
  Dest-router-id 1.1.1.11, Options 0x33, Metric 2
  Gen timer 00:19:03
  Aging timer 00:29:03
  Installed 00:30:57 ago, expires in 00:29:03, sent 00:30:55 ago
  Last changed 01:20:41 ago, Change count: 2, Ours
                

That's all.

17-10-2014.