17 mins read
OSPF Virtual Link
1. Intro
For backbone areas only, create a virtual link to use in place of an actual physical link. All area border routers and other routing devices on the backbone must be contiguous. If this is not possible and there is a break in OSPF connectivity, use virtual links to create connectivity to the OSPF backbone. When configuring virtual links, you must configure links on the two routing devices that form the end points of the link, and both of these routing devices must be area border routers.
You cannot configure links through stub areas.
2. OSPF Initial Topology
We will modify a little the topology so that R2 is not directly connected to Area 0, as follows:
Let’s check the config on R1 and R2.
### R1 config:
set protocols ospf area 0.0.0.1 interface lo0.0 passive
set protocols ospf area 0.0.0.1 interface ge-0/0/2.0 interface-type p2p
set protocols ospf area 0.0.0.1 interface ge-0/0/2.0 metric 10
set protocols ospf area 0.0.0.1 interface ge-0/0/4.0 passive
set protocols ospf area 0.0.0.5 interface ge-0/0/1.0 interface-type p2p
set protocols ospf area 0.0.0.5 interface ge-0/0/1.0 metric 10
set protocols ospf export TO-OSPF
### R2 config:
set protocols ospf area 0.0.0.5 interface lo0.0 passive
set protocols ospf area 0.0.0.5 interface ge-0/0/1.0 interface-type p2p
set protocols ospf area 0.0.0.5 interface ge-0/0/1.0 metric 10
set protocols ospf area 0.0.0.5 interface ge-0/0/4.0 passiveSame as in the diagram, R2 is in Area 5, it has a session to R1 (Area 1), but no neighbors to Area 0.
This has an impact on the OSPF database and the routing table. Area 5 and Area 0 can’t see each other:
### R2 has no routes from Area 0 in the database:
root@R2# run show ospf database
OSPF database, Area 0.0.0.5
Type ID Adv Rtr Seq Age Opt Cksum Len
Router 17.0.0.1 17.0.0.1 0x80000002 29 0x22 0x7717 48
Router *17.0.0.2 17.0.0.2 0x80000002 28 0x22 0x54c7 108
Summary 10.1.1.0 17.0.0.1 0x80000001 133 0x22 0x5ac3 28
Summary 17.0.0.1 17.0.0.1 0x80000001 133 0x22 0x217 28
Summary 17.18.1.0 17.0.0.1 0x80000001 133 0x22 0x8c70 28
Summary 17.18.7.0 17.0.0.1 0x80000001 133 0x22 0xef10 28
Summary 128.49.247.1 17.0.0.1 0x80000001 133 0x22 0x631d 28
ASBRSum 17.0.0.3 17.0.0.1 0x80000001 133 0x22 0x44c7 28
OSPF AS SCOPE link state database
Type ID Adv Rtr Seq Age Opt Cksum Len
Extern 1.1.0.0 17.0.0.1 0x80000079 1732 0x22 0x57ce 36
Extern 2.2.0.0 17.0.0.6 0x80000080 2310 0x22 0xf29b 36
Extern 3.3.1.0 17.0.0.5 0x800000ca 1677 0x22 0x5f6c 36
Extern 3.3.2.0 17.0.0.5 0x800000ca 927 0x22 0x5476 36
Extern 3.3.3.0 17.0.0.5 0x800000c9 2427 0x22 0x4b7f 36
Extern 4.4.1.0 17.0.0.3 0x800000cb 286 0x22 0x507a 36
Extern 4.4.2.0 17.0.0.3 0x800000ca 2257 0x22 0x4783 36
Extern 4.4.3.0 17.0.0.3 0x800000ca 2171 0x22 0x3c8d 36
### Although R3 has some R2 information in Area 1 database,
### it is not moved to the backbone (Area 0) database:
root@R3> show ospf database
OSPF database, Area 0.0.0.0
Type ID Adv Rtr Seq Age Opt Cksum Len
Router *17.0.0.3 17.0.0.3 0x80000150 1096 0x22 0x17a5 96
Router 17.0.0.4 17.0.0.4 0x800000ed 983 0x22 0x757c 132
Router 17.0.0.5 17.0.0.5 0x800000d1 389 0x22 0x24d9 96
Router 17.0.0.6 17.0.0.6 0x800000db 2134 0x22 0xbd01 96
Summary *10.1.1.0 17.0.0.3 0x80000092 1867 0x22 0x8ff0 28
Summary 10.2.1.0 17.0.0.6 0x8000009b 1456 0x22 0x5f14 28
Summary 10.2.2.0 17.0.0.6 0x8000009b 1359 0x22 0x541e 28
Summary 10.2.3.0 17.0.0.6 0x8000009b 1263 0x22 0x4928 28
Summary *17.0.0.1 17.0.0.3 0x80000092 1524 0x22 0x3744 28
Summary 17.0.0.7 17.0.0.6 0x8000009a 682 0x22 0xd891 28
Summary 17.0.0.8 17.0.0.6 0x8000009a 585 0x22 0xce9a 28
Summary *17.18.0.0 17.0.0.3 0x80000094 344 0x22 0x6ef8 28
Summary 17.18.0.0 17.0.0.4 0x80000097 201 0x22 0x580c 28
Summary 17.28.0.0 17.0.0.6 0x80000095 2714 0x22 0x3c14 28
ASBRSum *17.0.0.1 17.0.0.3 0x80000096 310 0x22 0x2155 28
OSPF database, Area 0.0.0.1
Type ID Adv Rtr Seq Age Opt Cksum Len
Router 17.0.0.1 17.0.0.1 0x800000d2 345 0x22 0xea9a 96
Router 17.0.0.2 17.0.0.2 0x800000d1 2537 0x22 0x9e0d 132
Router *17.0.0.3 17.0.0.3 0x800000e9 1953 0x22 0xadf2 48
Router 17.0.0.4 17.0.0.4 0x800000e8 1531 0x22 0xb4db 48
Summary *10.0.1.0 17.0.0.3 0x800000cc 1353 0x22 0x2720 28
Summary 10.0.1.0 17.0.0.4 0x800000cd 894 0x22 0xba94 28
Summary *10.0.2.0 17.0.0.3 0x800000cc 1267 0x22 0x1c2a 28
Summary 10.0.2.0 17.0.0.4 0x800000cd 803 0x22 0xaf9e 28
Summary 10.1.2.0 17.0.0.1 0x80000001 241 0x22 0xb35f 28
Summary 10.1.3.0 17.0.0.1 0x80000001 241 0x22 0xa869 28
Summary *10.2.1.0 17.0.0.3 0x80000097 410 0x22 0xdd92 28
Summary 10.2.1.0 17.0.0.4 0x80000096 3167 0x22 0x3e28 28
Summary *10.2.2.0 17.0.0.3 0x80000098 324 0x22 0xd09d 28
Summary 10.2.2.0 17.0.0.4 0x80000097 3076 0x22 0x3133 28
Summary *10.2.3.0 17.0.0.3 0x80000098 239 0x22 0xc5a7 28
Summary 10.2.3.0 17.0.0.4 0x80000097 2985 0x22 0x263d 28
Summary 17.0.0.2 17.0.0.1 0x80000001 241 0x22 0x5cb1 28
Summary *17.0.0.3 17.0.0.3 0x800000e3 2296 0x22 0x1c16 28
Summary 17.0.0.3 17.0.0.4 0x800000e5 1985 0x22 0x76ae 28
Summary *17.0.0.4 17.0.0.3 0x800000e4 2124 0x22 0x74b1 28
Summary 17.0.0.4 17.0.0.4 0x800000e3 2167 0x22 0xc24 28
Summary *17.0.0.5 17.0.0.3 0x800000d1 153 0x22 0xf439 28
Summary 17.0.0.5 17.0.0.4 0x800000cb 1803 0x22 0x96a6 28
Summary *17.0.0.6 17.0.0.3 0x800000ce 1010 0x22 0x8cad 28
Summary 17.0.0.6 17.0.0.4 0x800000ce 712 0x22 0xea44 28
Summary *17.0.0.7 17.0.0.3 0x80000097 67 0x22 0x5511 28
Summary 17.0.0.7 17.0.0.4 0x80000096 2894 0x22 0xb5a6 28
Summary *17.0.0.8 17.0.0.3 0x80000097 2981 0x22 0x4b1a 28
Summary 17.0.0.8 17.0.0.4 0x80000097 2803 0x22 0xa9b0 28
Summary *17.8.0.0 17.0.0.3 0x80000090 753 0x22 0x4923 28
Summary 17.8.0.0 17.0.0.4 0x8000008e 3350 0x22 0x4726 28
Summary 17.18.0.0 17.0.0.1 0x80000001 345 0x22 0x9766 28
Summary 17.18.10.0 17.0.0.1 0x80000001 241 0x22 0x33bf 28
Summary *17.28.0.0 17.0.0.3 0x80000094 2896 0x22 0xb495 28
Summary 17.28.0.0 17.0.0.4 0x80000094 2712 0x22 0x132c 28
ASBRSum 17.0.0.3 17.0.0.4 0x800000ea 2350 0x22 0x5ec0 28
ASBRSum *17.0.0.5 17.0.0.3 0x800000cd 2553 0x22 0xee42 28
ASBRSum 17.0.0.5 17.0.0.4 0x800000ca 2258 0x22 0x8ab2 28
ASBRSum *17.0.0.6 17.0.0.3 0x800000cd 839 0x22 0x80b9 28
ASBRSum 17.0.0.6 17.0.0.4 0x800000cd 531 0x22 0xde50 28
OSPF AS SCOPE link state database
Type ID Adv Rtr Seq Age Opt Cksum Len
Extern 1.1.0.0 17.0.0.1 0x80000079 1944 0x22 0x57ce 36
Extern 2.2.0.0 17.0.0.6 0x80000080 2521 0x22 0xf29b 36
Extern 3.3.1.0 17.0.0.5 0x800000ca 1889 0x22 0x5f6c 36
Extern 3.3.2.0 17.0.0.5 0x800000ca 1139 0x22 0x5476 36
Extern 3.3.3.0 17.0.0.5 0x800000c9 2639 0x22 0x4b7f 36
Extern *4.4.1.0 17.0.0.3 0x800000cb 496 0x22 0x507a 36
Extern *4.4.2.0 17.0.0.3 0x800000ca 2467 0x22 0x4783 36
Extern *4.4.3.0 17.0.0.3 0x800000ca 2381 0x22 0x3c8d 36
### Also interesting to note that Type 5 LSAs (Extern area passing unrestricted)
### But as we will see next, Type 5 LSAs are not installed in the routing table. We can see the same in the routing table. To be explicit:
- we are missing R3, R4, R5, … (and so on) loopbacks
- we are missing the 10.1.x.x, 10.2.x.x and 10.3.x.x routes
- Even if we have the LSA in the OSPF database, we are even missing the External routes 2.2.x.x, 3.3.x.x, 4.4.x.x routes
root@R2# run show route
inet.0: 31 destinations, 31 routes (31 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
1.1.0.0/16 *[OSPF/150] 00:19:04, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
4.4.1.0/24 *[OSPF/150] 00:19:04, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
4.4.2.0/24 *[OSPF/150] 00:19:04, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
4.4.3.0/24 *[OSPF/150] 00:19:04, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
10.1.1.0/24 *[OSPF/10] 00:19:04, metric 11
> to 17.18.0.1 via ge-0/0/1.0
10.1.2.0/24 *[Direct/0] 1w0d 00:35:47
> via ge-0/0/4.0
10.1.2.1/32 *[Local/0] 1w0d 00:35:47
Local via ge-0/0/4.0
10.1.3.0/24 *[Direct/0] 1w0d 00:35:47
> via ge-0/0/4.0
10.1.3.1/32 *[Local/0] 1w0d 00:35:47
Local via ge-0/0/4.0
17.0.0.1/32 *[OSPF/10] 00:19:04, metric 10
> to 17.18.0.1 via ge-0/0/1.0
17.0.0.2/32 *[Direct/0] 1w3d 21:42:42
> via lo0.0
17.18.0.0/24 *[Direct/0] 5d 00:26:47
> via ge-0/0/1.0
17.18.0.2/32 *[Local/0] 5d 00:26:47
Local via ge-0/0/1.0
17.18.1.0/24 *[OSPF/10] 00:19:04, metric 20
> to 17.18.0.1 via ge-0/0/1.0
17.18.7.0/24 *[OSPF/10] 00:19:04, metric 11
> to 17.18.0.1 via ge-0/0/1.0
17.18.8.0/24 *[Direct/0] 5d 00:06:33
> via ge-0/0/2.0
17.18.8.1/32 *[Local/0] 5d 00:06:33
Local via ge-0/0/2.0
17.18.9.0/24 *[Direct/0] 5d 00:22:52
> via ge-0/0/3.0
17.18.9.1/32 *[Local/0] 5d 00:22:52
Local via ge-0/0/3.0
17.18.10.0/24 *[Direct/0] 5d 00:07:20
> via ge-0/0/4.0
17.18.10.1/32 *[Local/0] 5d 00:07:20
Local via ge-0/0/4.0Same on R3, we are missing R2 loopback and 10.1.2.x, 10.1.3.x routes:
root@R3> show route
inet.0: 53 destinations, 53 routes (53 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
1.1.0.0/16 *[OSPF/150] 4d 04:52:04, metric 0, tag 0
> to 17.18.1.1 via ge-0/0/1.0
2.2.0.0/16 *[OSPF/150] 3d 22:21:15, metric 20, tag 0
> to 17.8.4.2 via ge-0/0/2.0
3.3.1.0/24 *[OSPF/150] 3d 22:21:15, metric 0, tag 0
> to 17.8.4.2 via ge-0/0/2.0
to 17.8.11.2 via ge-0/0/4.0
3.3.2.0/24 *[OSPF/150] 3d 22:21:15, metric 0, tag 0
> to 17.8.4.2 via ge-0/0/2.0
to 17.8.11.2 via ge-0/0/4.0
3.3.3.0/24 *[OSPF/150] 3d 22:21:15, metric 0, tag 0
> to 17.8.4.2 via ge-0/0/2.0
to 17.8.11.2 via ge-0/0/4.0
4.4.1.0/24 *[Static/5] 6d 23:45:12
> to 17.8.12.2 via ge-0/0/5.0
4.4.2.0/24 *[Static/5] 6d 23:45:12
> to 17.8.12.2 via ge-0/0/5.0
4.4.3.0/24 *[Static/5] 6d 23:45:12
> to 17.8.12.2 via ge-0/0/5.0
10.0.1.0/24 *[OSPF/10] 1w0d 00:25:09, metric 11
> to 17.8.11.2 via ge-0/0/4.0
10.0.2.0/24 *[OSPF/10] 1w0d 00:25:09, metric 11
> to 17.8.11.2 via ge-0/0/4.0
10.1.1.0/24 *[OSPF/10] 5d 00:30:31, metric 11
> to 17.18.1.1 via ge-0/0/1.0
10.2.1.0/24 *[OSPF/10] 3d 22:21:15, metric 21
> to 17.8.4.2 via ge-0/0/2.0
10.2.2.0/24 *[OSPF/10] 3d 22:21:15, metric 21
> to 17.8.4.2 via ge-0/0/2.0
10.2.3.0/24 *[OSPF/10] 3d 22:21:15, metric 21
> to 17.8.4.2 via ge-0/0/2.0
17.0.0.1/32 *[OSPF/10] 5d 00:30:31, metric 10
> to 17.18.1.1 via ge-0/0/1.0
17.0.0.3/32 *[Direct/0] 1w3d 21:45:36
> via lo0.0
17.0.0.4/32 *[OSPF/10] 1w0d 00:30:14, metric 10
> to 17.8.11.2 via ge-0/0/4.0
17.0.0.5/32 *[OSPF/10] 3d 22:21:15, metric 20
> to 17.8.4.2 via ge-0/0/2.0
to 17.8.11.2 via ge-0/0/4.0
17.0.0.6/32 *[OSPF/10] 3d 22:25:46, metric 10
> to 17.8.4.2 via ge-0/0/2.0
17.0.0.7/32 *[OSPF/10] 3d 22:21:15, metric 20
> to 17.8.4.2 via ge-0/0/2.0
17.0.0.8/32 *[OSPF/10] 3d 22:21:15, metric 20
> to 17.8.4.2 via ge-0/0/2.0
17.8.0.0/16 *[OSPF/10] 4d 21:31:08, metric 16777215
Discard
17.8.2.0/24 *[OSPF/10] 1w0d 00:25:09, metric 11
> to 17.8.11.2 via ge-0/0/4.0
17.8.3.0/24 *[OSPF/10] 1w0d 00:26:31, metric 20
> to 17.8.11.2 via ge-0/0/4.0
17.8.4.0/24 *[Direct/0] 1w3d 21:45:36
> via ge-0/0/2.0
17.8.4.1/32 *[Local/0] 1w3d 21:45:36
Local via ge-0/0/2.0
17.8.8.0/24 *[Direct/0] 1w3d 21:45:36
> via ge-0/0/3.0
17.8.8.2/32 *[Local/0] 1w3d 21:45:36
Local via ge-0/0/3.0
17.8.11.0/24 *[Direct/0] 1w0d 21:16:51
> via ge-0/0/4.0
17.8.11.1/32 *[Local/0] 1w0d 21:16:51
Local via ge-0/0/4.0
17.8.12.0/24 *[Direct/0] 1w3d 21:45:36
> via ge-0/0/5.0
17.8.12.1/32 *[Local/0] 1w3d 21:45:36
Local via ge-0/0/5.0
17.8.13.0/24 *[OSPF/10] 3d 22:25:46, metric 20
> to 17.8.4.2 via ge-0/0/2.0
17.18.0.0/16 *[OSPF/10] 4d 21:46:25, metric 16777215
Discard
17.18.1.0/24 *[Direct/0] 5d 00:30:36
> via ge-0/0/1.0
17.18.1.2/32 *[Local/0] 5d 00:30:36
Local via ge-0/0/1.0
17.18.7.0/24 *[OSPF/10] 5d 00:16:26, metric 11
> to 17.18.1.1 via ge-0/0/1.0
17.28.0.0/16 *[OSPF/10] 3d 22:21:15, metric 30
> to 17.8.4.2 via ge-0/0/2.03. OSPF Virtual Link configuration:
First we must already have a router-id, which we have: set routing-options router-id 17.0.0.x.
We will configure a virtual link from R1 (Area 5 ABR) to R3 (Area 0 ABR).
### Config on R1:
root@R1# set protocols ospf area 0 virtual-link neighbor-id 17.0.0.3 transit-area 1
[edit]
root@R1# show | compare
[edit protocols ospf]
area 0.0.0.5 { ... }
+ area 0.0.0.0 {
+ virtual-link neighbor-id 17.0.0.3 transit-area 0.0.0.1;
+ }
[edit]
root@R1# commit
commit complete
### Next, config on R3:
root@R3# set protocols ospf area 0 virtual-link neighbor-id 17.0.0.1 transit-area 1
[edit]
root@R3# show | compare
[edit protocols ospf area 0.0.0.0]
+ virtual-link neighbor-id 17.0.0.1 transit-area 0.0.0.1;
[edit]
root@R3# commit
commit completeNow we can see that we have an OSPF neighborship on the virtual link:
root@R1# run show ospf interface
Interface State Area DR ID BDR ID Nbrs
ge-0/0/2.0 PtToPt 0.0.0.1 0.0.0.0 0.0.0.0 1
ge-0/0/4.0 DRother 0.0.0.1 0.0.0.0 0.0.0.0 0
ge-0/0/4.0 DRother 0.0.0.1 0.0.0.0 0.0.0.0 0
lo0.0 DRother 0.0.0.1 0.0.0.0 0.0.0.0 0
lo0.0 DRother 0.0.0.1 0.0.0.0 0.0.0.0 0
ge-0/0/1.0 PtToPt 0.0.0.5 0.0.0.0 0.0.0.0 1
vl-17.0.0.3 PtToPt 0.0.0.0 0.0.0.0 0.0.0.0 1
root@R1# run show ospf neighbor
Address Interface State ID Pri Dead
17.18.1.2 ge-0/0/2.0 Full 17.0.0.3 128 36
17.18.0.2 ge-0/0/1.0 Full 17.0.0.2 128 33
17.18.1.2 vl-17.0.0.3 Full 17.0.0.3 0 36
root@R3# run show ospf interface
Interface State Area DR ID BDR ID Nbrs
ge-0/0/2.0 PtToPt 0.0.0.0 0.0.0.0 0.0.0.0 1
ge-0/0/4.0 PtToPt 0.0.0.0 0.0.0.0 0.0.0.0 1
lo0.0 DRother 0.0.0.0 0.0.0.0 0.0.0.0 0
lo0.0 DRother 0.0.0.0 0.0.0.0 0.0.0.0 0
vl-17.0.0.1 PtToPt 0.0.0.0 0.0.0.0 0.0.0.0 1
ge-0/0/1.0 PtToPt 0.0.0.1 0.0.0.0 0.0.0.0 1
root@R3# run show ospf neighbor
Address Interface State ID Pri Dead
17.8.4.2 ge-0/0/2.0 Full 17.0.0.6 128 38
17.8.11.2 ge-0/0/4.0 Full 17.0.0.4 128 38
17.18.1.1 vl-17.0.0.1 Full 17.0.0.1 0 36
17.18.1.1 ge-0/0/1.0 Full 17.0.0.1 128 32And finally the OSPF database and routing table now are ok:
### We now can see the missing prefixes on R2:
root@R2> show ospf database
OSPF database, Area 0.0.0.5
Type ID Adv Rtr Seq Age Opt Cksum Len
Router 17.0.0.1 17.0.0.1 0x80000005 1332 0x22 0x711a 48
Router *17.0.0.2 17.0.0.2 0x80000004 1849 0x22 0x50c9 108
Summary 10.0.1.0 17.0.0.1 0x80000003 256 0x22 0x2bdd 28
Summary 10.0.2.0 17.0.0.1 0x80000003 200 0x22 0x20e7 28
Summary 10.1.1.0 17.0.0.1 0x80000004 1671 0x22 0x54c6 28
Summary 10.2.1.0 17.0.0.1 0x80000003 143 0x22 0x7785 28
Summary 10.2.2.0 17.0.0.1 0x80000003 86 0x22 0x6c8f 28
Summary 10.2.3.0 17.0.0.1 0x80000003 30 0x22 0x6199 28
Summary 17.0.0.1 17.0.0.1 0x80000004 1615 0x22 0xfb1a 28
Summary 17.0.0.3 17.0.0.1 0x80000002 2942 0x22 0x50bb 28
Summary 17.0.0.4 17.0.0.1 0x80000002 2887 0x22 0xaa56 28
Summary 17.0.0.5 17.0.0.1 0x80000002 2832 0x22 0x5f0 28
Summary 17.0.0.6 17.0.0.1 0x80000002 2777 0x22 0x9668 28
Summary 17.0.0.7 17.0.0.1 0x80000002 2722 0x22 0xf003 28
Summary 17.0.0.8 17.0.0.1 0x80000002 2667 0x22 0xe60c 28
Summary 17.8.2.0 17.0.0.1 0x80000002 2611 0x22 0x6693 28
Summary 17.8.3.0 17.0.0.1 0x80000002 2556 0x22 0xb53a 28
Summary 17.8.4.0 17.0.0.1 0x80000002 2501 0x22 0x46b2 28
Summary 17.8.11.0 17.0.0.1 0x80000002 2446 0x22 0xf8f8 28
Summary 17.8.13.0 17.0.0.1 0x80000002 2391 0x22 0x479e 28
Summary 17.18.1.0 17.0.0.1 0x80000004 1501 0x22 0x8673 28
Summary 17.18.7.0 17.0.0.1 0x80000004 1445 0x22 0xe913 28
Summary 17.28.0.0 17.0.0.1 0x80000002 2336 0x22 0x4a8a 28
ASBRSum 17.0.0.3 17.0.0.1 0x80000004 1950 0x22 0x3eca 28
ASBRSum 17.0.0.5 17.0.0.1 0x80000002 1840 0x22 0xf6fd 28
ASBRSum 17.0.0.6 17.0.0.1 0x80000002 1785 0x22 0x8875 28
OSPF AS SCOPE link state database
Type ID Adv Rtr Seq Age Opt Cksum Len
Extern 1.1.0.0 17.0.0.1 0x8000007c 1728 0x22 0x51d1 36
Extern 2.2.0.0 17.0.0.6 0x80000083 1444 0x22 0xec9e 36
Extern 3.3.1.0 17.0.0.5 0x800000cd 500 0x22 0x596f 36
Extern 3.3.2.0 17.0.0.5 0x800000cc 2750 0x22 0x5078 36
Extern 3.3.3.0 17.0.0.5 0x800000cc 1250 0x22 0x4582 36
Extern 4.4.1.0 17.0.0.3 0x800000ce 21 0x22 0x4a7d 36
Extern 4.4.2.0 17.0.0.3 0x800000cd 1221 0x22 0x4186 36
Extern 4.4.3.0 17.0.0.3 0x800000cd 1135 0x22 0x3690 36
root@R2> show route
inet.0: 58 destinations, 58 routes (58 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
1.1.0.0/16 *[OSPF/150] 02:10:53, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
2.2.0.0/16 *[OSPF/150] 01:19:47, metric 40, tag 0
> to 17.18.0.1 via ge-0/0/1.0
3.3.1.0/24 *[OSPF/150] 01:19:47, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
3.3.2.0/24 *[OSPF/150] 01:19:47, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
3.3.3.0/24 *[OSPF/150] 01:19:47, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
4.4.1.0/24 *[OSPF/150] 02:10:53, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
4.4.2.0/24 *[OSPF/150] 02:10:53, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
4.4.3.0/24 *[OSPF/150] 02:10:53, metric 0, tag 0
> to 17.18.0.1 via ge-0/0/1.0
10.0.1.0/24 *[OSPF/10] 01:19:47, metric 31
> to 17.18.0.1 via ge-0/0/1.0
10.0.2.0/24 *[OSPF/10] 01:19:47, metric 31
> to 17.18.0.1 via ge-0/0/1.0
10.1.1.0/24 *[OSPF/10] 02:10:53, metric 11
> to 17.18.0.1 via ge-0/0/1.0
10.1.2.0/24 *[Direct/0] 1w0d 02:27:36
> via ge-0/0/4.0
10.1.2.1/32 *[Local/0] 1w0d 02:27:36
Local via ge-0/0/4.0
10.1.3.0/24 *[Direct/0] 1w0d 02:27:36
> via ge-0/0/4.0
10.1.3.1/32 *[Local/0] 1w0d 02:27:36
Local via ge-0/0/4.0
10.2.1.0/24 *[OSPF/10] 01:19:47, metric 41
> to 17.18.0.1 via ge-0/0/1.0
10.2.2.0/24 *[OSPF/10] 01:19:47, metric 41
> to 17.18.0.1 via ge-0/0/1.0
10.2.3.0/24 *[OSPF/10] 01:19:47, metric 41
> to 17.18.0.1 via ge-0/0/1.0
17.0.0.1/32 *[OSPF/10] 02:10:53, metric 10
> to 17.18.0.1 via ge-0/0/1.0
17.0.0.2/32 *[Direct/0] 1w3d 23:34:31
> via lo0.0
17.0.0.3/32 *[OSPF/10] 01:19:47, metric 20
> to 17.18.0.1 via ge-0/0/1.0
17.0.0.4/32 *[OSPF/10] 01:19:47, metric 30
> to 17.18.0.1 via ge-0/0/1.0
17.0.0.5/32 *[OSPF/10] 01:19:47, metric 40
> to 17.18.0.1 via ge-0/0/1.0
17.0.0.6/32 *[OSPF/10] 01:19:47, metric 30
> to 17.18.0.1 via ge-0/0/1.0
17.0.0.7/32 *[OSPF/10] 01:19:47, metric 40
> to 17.18.0.1 via ge-0/0/1.0
17.0.0.8/32 *[OSPF/10] 01:19:47, metric 40
> to 17.18.0.1 via ge-0/0/1.0
17.8.2.0/24 *[OSPF/10] 01:19:47, metric 31
> to 17.18.0.1 via ge-0/0/1.0
17.8.3.0/24 *[OSPF/10] 01:19:47, metric 40
> to 17.18.0.1 via ge-0/0/1.0
17.8.4.0/24 *[OSPF/10] 01:19:47, metric 30
> to 17.18.0.1 via ge-0/0/1.0
17.8.11.0/24 *[OSPF/10] 01:19:47, metric 30
> to 17.18.0.1 via ge-0/0/1.0
17.8.13.0/24 *[OSPF/10] 01:19:47, metric 40
> to 17.18.0.1 via ge-0/0/1.0
17.18.0.0/24 *[Direct/0] 5d 02:18:36
> via ge-0/0/1.0
17.18.0.2/32 *[Local/0] 5d 02:18:36
Local via ge-0/0/1.0
17.18.1.0/24 *[OSPF/10] 02:10:53, metric 20
> to 17.18.0.1 via ge-0/0/1.0
17.18.7.0/24 *[OSPF/10] 02:10:53, metric 11
> to 17.18.0.1 via ge-0/0/1.0
17.18.8.0/24 *[Direct/0] 5d 01:58:22
> via ge-0/0/2.0
17.18.8.1/32 *[Local/0] 5d 01:58:22
Local via ge-0/0/2.0
17.18.9.0/24 *[Direct/0] 5d 02:14:41
> via ge-0/0/3.0
17.18.9.1/32 *[Local/0] 5d 02:14:41
Local via ge-0/0/3.0
17.18.10.0/24 *[Direct/0] 5d 01:59:09
> via ge-0/0/4.0
17.18.10.1/32 *[Local/0] 5d 01:59:09
Local via ge-0/0/4.0
17.28.0.0/16 *[OSPF/10] 01:19:47, metric 50
> to 17.18.0.1 via ge-0/0/1.0
### We now can see the missing prefixes on R3:
root@R3# run show ospf database
OSPF database, Area 0.0.0.0
Type ID Adv Rtr Seq Age Opt Cksum Len
Router 17.0.0.1 17.0.0.1 0x80000001 61 0x22 0x7354 36
Router *17.0.0.3 17.0.0.3 0x80000153 60 0x22 0x2343 108
Router 17.0.0.4 17.0.0.4 0x800000ee 1585 0x22 0x737d 132
Router 17.0.0.5 17.0.0.5 0x800000d2 274 0x22 0x22da 96
Router 17.0.0.6 17.0.0.6 0x800000dc 2019 0x22 0xbb02 96
Summary 10.1.1.0 17.0.0.1 0x80000001 110 0x22 0x5ac3 28
Summary *10.1.1.0 17.0.0.3 0x80000093 1752 0x22 0x8df1 28
Summary 10.1.2.0 17.0.0.1 0x80000001 110 0x22 0xb35f 28
Summary 10.1.3.0 17.0.0.1 0x80000001 110 0x22 0xa869 28
Summary 10.2.1.0 17.0.0.6 0x8000009c 1519 0x22 0x5d15 28
Summary 10.2.2.0 17.0.0.6 0x8000009c 1407 0x22 0x521f 28
Summary 10.2.3.0 17.0.0.6 0x8000009c 1296 0x22 0x4729 28
Summary 17.0.0.1 17.0.0.1 0x80000001 110 0x22 0x217 28
Summary *17.0.0.1 17.0.0.3 0x80000093 1654 0x22 0x3545 28
Summary 17.0.0.2 17.0.0.1 0x80000001 110 0x22 0x5cb1 28
Summary 17.0.0.7 17.0.0.6 0x8000009b 741 0x22 0xd692 28
Summary 17.0.0.8 17.0.0.6 0x8000009b 630 0x22 0xcc9b 28
Summary 17.18.0.0 17.0.0.1 0x80000001 110 0x22 0x9766 28
Summary *17.18.0.0 17.0.0.3 0x80000095 590 0x22 0x6cf9 28
Summary 17.18.0.0 17.0.0.4 0x80000098 240 0x22 0x560d 28
Summary 17.18.1.0 17.0.0.1 0x80000001 110 0x22 0x8c70 28
Summary 17.18.7.0 17.0.0.1 0x80000001 110 0x22 0xef10 28
Summary 17.18.10.0 17.0.0.1 0x80000001 110 0x22 0x33bf 28
Summary 17.28.0.0 17.0.0.6 0x80000096 2681 0x22 0x3a15 28
ASBRSum *17.0.0.1 17.0.0.3 0x80000098 60 0x22 0x1d57 28
ASBRSum 17.0.0.3 17.0.0.1 0x80000002 61 0x22 0x42c8 28
OSPF database, Area 0.0.0.1
Type ID Adv Rtr Seq Age Opt Cksum Len
Router 17.0.0.1 17.0.0.1 0x800000d4 61 0x22 0xf28c 96
Router *17.0.0.3 17.0.0.3 0x800000eb 60 0x22 0xb5e4 48
Summary *10.0.1.0 17.0.0.3 0x800000cd 1557 0x22 0x2521 28
Summary *10.0.2.0 17.0.0.3 0x800000cd 1460 0x22 0x1a2b 28
Summary 10.1.2.0 17.0.0.1 0x80000002 888 0x22 0xb160 28
Summary 10.1.3.0 17.0.0.1 0x80000002 697 0x22 0xa66a 28
Summary *10.2.1.0 17.0.0.3 0x80000098 687 0x22 0xdb93 28
Summary *10.2.2.0 17.0.0.3 0x80000099 493 0x22 0xce9e 28
Summary *10.2.3.0 17.0.0.3 0x80000099 300 0x22 0xc3a8 28
Summary 17.0.0.2 17.0.0.1 0x80000002 507 0x22 0x5ab2 28
Summary *17.0.0.3 17.0.0.3 0x800000e4 2181 0x22 0x1a17 28
Summary *17.0.0.4 17.0.0.3 0x800000e5 2009 0x22 0x72b2 28
Summary *17.0.0.5 17.0.0.3 0x800000d2 203 0x22 0xf23a 28
Summary *17.0.0.6 17.0.0.3 0x800000cf 1170 0x22 0x8aae 28
Summary 17.0.0.6 17.0.0.4 0x800000ce 3597 0x22 0xea44 28
Summary *17.0.0.7 17.0.0.3 0x80000098 106 0x22 0x5312 28
Summary *17.0.0.8 17.0.0.3 0x80000099 10 0x22 0x471c 28
Summary *17.8.2.0 17.0.0.3 0x80000001 60 0x22 0xf70b 28
Summary *17.8.3.0 17.0.0.3 0x80000001 60 0x22 0x47b1 28
Summary *17.8.4.0 17.0.0.3 0x80000001 60 0x22 0xd72a 28
Summary *17.8.11.0 17.0.0.3 0x80000001 60 0x22 0x8a70 28
Summary *17.8.13.0 17.0.0.3 0x80000001 60 0x22 0xd816 28
Summary 17.18.0.0 17.0.0.1 0x80000002 2030 0x22 0x9567 28
Summary 17.18.10.0 17.0.0.1 0x80000002 316 0x22 0x31c0 28
Summary *17.28.0.0 17.0.0.3 0x80000095 2781 0x22 0xb296 28
ASBRSum *17.0.0.5 17.0.0.3 0x800000ce 2438 0x22 0xec43 28
ASBRSum *17.0.0.6 17.0.0.3 0x800000ce 977 0x22 0x7eba 28
ASBRSum 17.0.0.6 17.0.0.4 0x800000cd 3416 0x22 0xde50 28
OSPF AS SCOPE link state database
Type ID Adv Rtr Seq Age Opt Cksum Len
Extern 1.1.0.0 17.0.0.1 0x8000007a 2792 0x22 0x55cf 36
Extern 2.2.0.0 17.0.0.6 0x80000081 2458 0x22 0xf09c 36
Extern 3.3.1.0 17.0.0.5 0x800000cb 1774 0x22 0x5d6d 36
Extern 3.3.2.0 17.0.0.5 0x800000cb 1024 0x22 0x5277 36
Extern 3.3.3.0 17.0.0.5 0x800000ca 2524 0x22 0x4980 36
Extern *4.4.1.0 17.0.0.3 0x800000cc 783 0x22 0x4e7b 36
Extern *4.4.2.0 17.0.0.3 0x800000cb 2352 0x22 0x4584 36
Extern *4.4.3.0 17.0.0.3 0x800000cb 2266 0x22 0x3a8e 36
### Interesting to point out that R3 doesn't have an Area 5 database.
### Only R2 and R3 have an OSPF database for Area 5.
[edit]
root@R3# run show route
inet.0: 59 destinations, 59 routes (59 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both
1.1.0.0/16 *[OSPF/150] 4d 05:21:44, metric 0, tag 0
> to 17.18.1.1 via ge-0/0/1.0
2.2.0.0/16 *[OSPF/150] 3d 22:50:55, metric 20, tag 0
> to 17.8.4.2 via ge-0/0/2.0
3.3.1.0/24 *[OSPF/150] 3d 22:50:55, metric 0, tag 0
> to 17.8.4.2 via ge-0/0/2.0
to 17.8.11.2 via ge-0/0/4.0
3.3.2.0/24 *[OSPF/150] 3d 22:50:55, metric 0, tag 0
> to 17.8.4.2 via ge-0/0/2.0
to 17.8.11.2 via ge-0/0/4.0
3.3.3.0/24 *[OSPF/150] 3d 22:50:55, metric 0, tag 0
> to 17.8.4.2 via ge-0/0/2.0
to 17.8.11.2 via ge-0/0/4.0
4.4.1.0/24 *[Static/5] 1w0d 00:14:52
> to 17.8.12.2 via ge-0/0/5.0
4.4.2.0/24 *[Static/5] 1w0d 00:14:52
> to 17.8.12.2 via ge-0/0/5.0
4.4.3.0/24 *[Static/5] 1w0d 00:14:52
> to 17.8.12.2 via ge-0/0/5.0
10.0.1.0/24 *[OSPF/10] 1w0d 00:54:49, metric 11
> to 17.8.11.2 via ge-0/0/4.0
10.0.2.0/24 *[OSPF/10] 1w0d 00:54:49, metric 11
> to 17.8.11.2 via ge-0/0/4.0
10.1.1.0/24 *[OSPF/10] 5d 01:00:11, metric 11
> to 17.18.1.1 via ge-0/0/1.0
10.1.2.0/24 *[OSPF/10] 00:02:16, metric 21
> to 17.18.1.1 via ge-0/0/1.0
10.1.3.0/24 *[OSPF/10] 00:02:16, metric 21
> to 17.18.1.1 via ge-0/0/1.0
10.2.1.0/24 *[OSPF/10] 3d 22:50:55, metric 21
> to 17.8.4.2 via ge-0/0/2.0
10.2.2.0/24 *[OSPF/10] 3d 22:50:55, metric 21
> to 17.8.4.2 via ge-0/0/2.0
10.2.3.0/24 *[OSPF/10] 3d 22:50:55, metric 21
> to 17.8.4.2 via ge-0/0/2.0
17.0.0.1/32 *[OSPF/10] 5d 01:00:11, metric 10
> to 17.18.1.1 via ge-0/0/1.0
17.0.0.2/32 *[OSPF/10] 00:02:16, metric 20
> to 17.18.1.1 via ge-0/0/1.0
17.0.0.3/32 *[Direct/0] 1w3d 22:15:16
> via lo0.0
17.0.0.4/32 *[OSPF/10] 1w0d 00:59:54, metric 10
> to 17.8.11.2 via ge-0/0/4.0
17.0.0.5/32 *[OSPF/10] 3d 22:50:55, metric 20
> to 17.8.4.2 via ge-0/0/2.0
to 17.8.11.2 via ge-0/0/4.0
17.0.0.6/32 *[OSPF/10] 3d 22:55:26, metric 10
> to 17.8.4.2 via ge-0/0/2.0
17.0.0.7/32 *[OSPF/10] 3d 22:50:55, metric 20
> to 17.8.4.2 via ge-0/0/2.0
17.0.0.8/32 *[OSPF/10] 3d 22:50:55, metric 20
> to 17.8.4.2 via ge-0/0/2.0
17.8.0.0/16 *[OSPF/10] 4d 22:00:48, metric 16777215
Discard
17.8.2.0/24 *[OSPF/10] 1w0d 00:54:49, metric 11
> to 17.8.11.2 via ge-0/0/4.0
17.8.3.0/24 *[OSPF/10] 1w0d 00:56:11, metric 20
> to 17.8.11.2 via ge-0/0/4.0
17.8.4.0/24 *[Direct/0] 1w3d 22:15:16
> via ge-0/0/2.0
17.8.4.1/32 *[Local/0] 1w3d 22:15:16
Local via ge-0/0/2.0
17.8.8.0/24 *[Direct/0] 1w3d 22:15:16
> via ge-0/0/3.0
17.8.8.2/32 *[Local/0] 1w3d 22:15:16
Local via ge-0/0/3.0
17.8.11.0/24 *[Direct/0] 1w0d 21:46:31
> via ge-0/0/4.0
17.8.11.1/32 *[Local/0] 1w0d 21:46:31
Local via ge-0/0/4.0
17.8.12.0/24 *[Direct/0] 1w3d 22:15:16
> via ge-0/0/5.0
17.8.12.1/32 *[Local/0] 1w3d 22:15:16
Local via ge-0/0/5.0
17.8.13.0/24 *[OSPF/10] 3d 22:55:26, metric 20
> to 17.8.4.2 via ge-0/0/2.0
17.18.0.0/16 *[OSPF/10] 4d 22:16:05, metric 16777215
Discard
17.18.0.0/24 *[OSPF/10] 00:02:16, metric 20
> to 17.18.1.1 via ge-0/0/1.0
17.18.1.0/24 *[Direct/0] 5d 01:00:16
> via ge-0/0/1.0
17.18.1.2/32 *[Local/0] 5d 01:00:16
Local via ge-0/0/1.0
17.18.7.0/24 *[OSPF/10] 5d 00:46:06, metric 11
> to 17.18.1.1 via ge-0/0/1.0
17.18.10.0/24 *[OSPF/10] 00:02:16, metric 21
> to 17.18.1.1 via ge-0/0/1.0
17.28.0.0/16 *[OSPF/10] 3d 22:50:55, metric 30
> to 17.8.4.2 via ge-0/0/2.0External Resources: