WALKTHROUGH: Build the Backbone

So you're stuck or don't trust your work. Here is the cheat/check page. Note that this is all done from the perspective of J2300-1. Adapt to other routers as needed.

  1. On interface fe-0/0/1 on each J2300 router, setup an OSPF backbone
    2. admin@J2300-1> edit 
Entering configuration mode

[edit]
admin@J2300-1# edit interfaces 

[edit interfaces]
admin@J2300-1# set fe-0/0/1 unit 12 family inet address 10.0.12.1/24 

[edit interfaces]
admin@J2300-1# set fe-0/0/1 unit 13 family inet address 10.0.13.1/24    

[edit interfaces]
admin@J2300-1# set fe-0/0/1 unit 12 vlan-id 12 

[edit interfaces]
admin@J2300-1# set fe-0/0/1 unit 13 vlan-id 13    

[edit interfaces]
admin@J2300-1# top 

[edit]
admin@J2300-1# edit protocols ospf   

[edit protocols ospf]
admin@J2300-1# edit area 0 

[edit protocols ospf area 0.0.0.0]
admin@J2300-1# set interface fe-0/0/1.12 

[edit protocols ospf area 0.0.0.0]
admin@J2300-1# set interface fe-0/0/1.13    

[edit protocols ospf area 0.0.0.0]
admin@J2300-1# commit 
commit complete
  2. Configure a loopback interface on your router and make sure it is advertised out to the backbone area
    3. [edit]
admin@J2300-1# edit interfaces 

[edit interfaces]
admin@J2300-1# set lo0 unit 0 family inet address 10.0.0.1 

[edit interfaces]
admin@J2300-1# top 
[edit]
admin@J2300-1# edit protocols ospf   

[edit protocols ospf]
admin@J2300-1# edit area 0 

[edit protocols ospf area 0.0.0.0]
admin@J2300-1# set interface lo0 

[edit protocols ospf area 0.0.0.0]
admin@J2300-1# commit
  3. Make sure your router has an OSPF adjacency on each Ethernet interface
    4. admin@J2300-1> show ospf interface  
Interface           State   Area            DR ID           BDR ID          Nbrs
fxp1.12             DR      0.0.0.0         10.0.0.1        10.0.0.2           1
fxp1.13             BDR     0.0.0.0         10.0.0.3        10.0.0.1           1
lo0.0               DR      0.0.0.0         10.0.0.1        0.0.0.0            0
  4. Make sure that you can ping every router's loopback address from your router
    5. admin@J2300-1> ping 10.0.0.2 count 1 
PING 10.0.0.2 (10.0.0.2): 56 data bytes
64 bytes from 10.0.0.2: icmp_seq=0 ttl=64 time=0.596 ms

--- 10.0.0.2 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.596/0.596/0.596/0.000 ms

admin@J2300-1> ping 10.0.0.3 count 1    
PING 10.0.0.3 (10.0.0.3): 56 data bytes
64 bytes from 10.0.0.3: icmp_seq=0 ttl=64 time=0.596 ms

--- 10.0.0.3 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 0.596/0.596/0.596/0.000 ms

admin@J2300-1> ping 10.0.0.4 count 1    
PING 10.0.0.4 (10.0.0.4): 56 data bytes
64 bytes from 10.0.0.4: icmp_seq=0 ttl=63 time=1.673 ms

--- 10.0.0.4 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 1.673/1.673/1.673/0.000 ms

admin@J2300-1> ping 10.0.0.5 count 1    
PING 10.0.0.5 (10.0.0.5): 56 data bytes
64 bytes from 10.0.0.5: icmp_seq=0 ttl=63 time=2.643 ms

--- 10.0.0.5 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 2.643/2.643/2.643/0.000 ms

admin@J2300-1> ping 10.0.0.6 count 1    
PING 10.0.0.6 (10.0.0.6): 56 data bytes
64 bytes from 10.0.0.6: icmp_seq=0 ttl=62 time=4.164 ms

--- 10.0.0.6 ping statistics ---
1 packets transmitted, 1 packets received, 0% packet loss
round-trip min/avg/max/stddev = 4.164/4.164/4.164/0.000 ms

admin@J2300-1>
  5. Examine the LSDB on your router
    6. admin@J2300-1> show ospf database 

    OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len 
Router  *10.0.0.1         10.0.0.1         0x8000000b  1840  0x22 0x2c49  60
Router   10.0.0.2         10.0.0.2         0x80000006  1807  0x22 0x82db  60
Router   10.0.0.3         10.0.0.3         0x80000008  2446  0x22 0x784e  72
Router   10.0.0.4         10.0.0.4         0x8000000a  1411  0x22 0x4945  72
Router   10.0.0.5         10.0.0.5         0x80000006  1376  0x22 0x1dc0  60
Router   10.0.0.6         10.0.0.6         0x80000005  1377  0x22 0x6a56  60
Network *10.0.12.1        10.0.0.1         0x80000004  1840  0x22 0x3fa   32
Network  10.0.13.3        10.0.0.3         0x80000004   989  0x22 0xdd1a  32
Network  10.0.24.4        10.0.0.4         0x80000003  1847  0x22 0x6e7b  32
Network  10.0.34.3        10.0.0.3         0x80000003   232  0x22 0x22be  32
Network  10.0.35.3        10.0.0.3         0x80000002  1717  0x22 0x27b8  32
Network  10.0.46.6        10.0.0.6         0x80000003  1416  0x22 0x8b40  32
Network  10.0.56.5        10.0.0.5         0x80000002  1376  0x22 0x4182  32
  6. Check your OSPF routing table
    7. admin@J2300-1> show ospf route 
Topology default Route Table:

Prefix             Path  Route      NH       Metric NextHop       Nexthop      
                   Type  Type       Type            Interface     Address/LSP
10.0.0.2           Intra Router     IP           10 fxp1.12       10.0.12.2
10.0.0.3           Intra Router     IP           10 fxp1.13       10.0.13.3
10.0.0.4           Intra Router     IP           20 fxp1.12       10.0.12.2
                                                    fxp1.13       10.0.13.3
10.0.0.5           Intra Router     IP           20 fxp1.13       10.0.13.3
10.0.0.6           Intra Router     IP           30 fxp1.12       10.0.12.2
                                                    fxp1.13       10.0.13.3
10.0.0.1/32        Intra Network    IP            0 lo0.0
10.0.0.2/32        Intra Network    IP           10 fxp1.12       10.0.12.2
10.0.0.3/32        Intra Network    IP           10 fxp1.13       10.0.13.3
10.0.0.4/32        Intra Network    IP           20 fxp1.12       10.0.12.2
                                                    fxp1.13       10.0.13.3
10.0.0.5/32        Intra Network    IP           20 fxp1.13       10.0.13.3
10.0.0.6/32        Intra Network    IP           30 fxp1.12       10.0.12.2
                                                    fxp1.13       10.0.13.3
10.0.12.0/24       Intra Network    IP           10 fxp1.12
10.0.13.0/24       Intra Network    IP           10 fxp1.13
10.0.24.0/24       Intra Network    IP           20 fxp1.12       10.0.12.2
10.0.34.0/24       Intra Network    IP           20 fxp1.13       10.0.13.3
10.0.35.0/24       Intra Network    IP           20 fxp1.13       10.0.13.3
10.0.46.0/24       Intra Network    IP           30 fxp1.12       10.0.12.2
                                                    fxp1.13       10.0.13.3
10.0.56.0/24       Intra Network    IP           30 fxp1.13       10.0.13.3

admin@J2300-1>
  7. Check your routing table for OSPF routes
    8. admin@J2300-1> show route protocol ospf   

inet.0: 20 destinations, 20 routes (20 active, 0 holddown, 0 hidden)
+ = Active Route, - = Last Active, * = Both

10.0.0.2/32        *[OSPF/10] 01:21:40, metric 10
                    > to 10.0.12.2 via fxp1.12
10.0.0.3/32        *[OSPF/10] 01:29:49, metric 10
                    > to 10.0.13.3 via fxp1.13
10.0.0.4/32        *[OSPF/10] 01:21:40, metric 20
                      to 10.0.12.2 via fxp1.12
                    > to 10.0.13.3 via fxp1.13
10.0.0.5/32        *[OSPF/10] 01:16:44, metric 20
                    > to 10.0.13.3 via fxp1.13
10.0.0.6/32        *[OSPF/10] 01:14:28, metric 30
                      to 10.0.12.2 via fxp1.12
                    > to 10.0.13.3 via fxp1.13
10.0.24.0/24       *[OSPF/10] 01:21:40, metric 20
                    > to 10.0.12.2 via fxp1.12
10.0.34.0/24       *[OSPF/10] 01:29:49, metric 20
                    > to 10.0.13.3 via fxp1.13
10.0.35.0/24       *[OSPF/10] 01:29:49, metric 20
                    > to 10.0.13.3 via fxp1.13
10.0.46.0/24       *[OSPF/10] 01:21:40, metric 30
                      to 10.0.12.2 via fxp1.12
                    > to 10.0.13.3 via fxp1.13
10.0.56.0/24       *[OSPF/10] 01:16:44, metric 30
                    > to 10.0.13.3 via fxp1.13
224.0.0.5/32       *[OSPF/10] 01:34:42, metric 1
                      MultiRecv

admin@J2300-1>
  8. Clear your OSPF database and observe the effects
    9. admin@J2300-1> clear ospf database    

admin@J2300-1> show ospf database     

    OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len 
Router  *10.0.0.1         10.0.0.1         0x80000010     1  0x22 0x9f02  60
Network *10.0.12.1        10.0.0.1         0x80000004  3600  0x22 0x3fa   32

admin@J2300-1> show ospf database    

    OSPF database, Area 0.0.0.0
 Type       ID               Adv Rtr           Seq      Age  Opt  Cksum  Len 
Router  *10.0.0.1         10.0.0.1         0x80000011     1  0x22 0xbbcc  60
Router   10.0.0.2         10.0.0.2         0x8000000c     2  0x22 0x80d6  60
Router   10.0.0.3         10.0.0.3         0x8000000b     9  0x22 0x21be  72
Router   10.0.0.4         10.0.0.4         0x8000000a  1524  0x22 0x4945  72
Router   10.0.0.5         10.0.0.5         0x80000006  1491  0x22 0x1dc0  60
Router   10.0.0.6         10.0.0.6         0x80000005  1490  0x22 0x6a56  60
Network *10.0.12.1        10.0.0.1         0x80000004  3600  0x22 0x3fa   32
Network  10.0.12.2        10.0.0.2         0x80000006     2  0x22 0xea0f  32
Network  10.0.24.4        10.0.0.4         0x80000003  1960  0x22 0x6e7b  32
Network  10.0.34.3        10.0.0.3         0x80000003   347  0x22 0x22be  32
Network  10.0.35.3        10.0.0.3         0x80000002  1832  0x22 0x27b8  32
Network  10.0.46.6        10.0.0.6         0x80000003  1529  0x22 0x8b40  32
Network  10.0.56.5        10.0.0.5         0x80000002  1491  0x22 0x4182  32

admin@J2300-1>