Home > BSCI, CCNP, LAB > BSCI – OSPF Lab

BSCI – OSPF Lab

OSPF is maybe the biggest topic of the BSCI (and ROUTE) exam(s). After the easy introduction and eventually not so scary EIGRP it is time for the heavy stuff and nothing is better than OSPF. I started with the first three videos which cover the basic concepts and implementation and built a lab that has all the basic options.
Before I start I have to admit that so far it is not bad at all, I feel good with the basics and had no problem capturing the lab. EIGRP was either harder (which I doubt) or just a great start that prepared me and got me in the right zone 🙂

BSCI - OSPF Lab

This lab has four routers, R1 with Serial & Loopback Interfaces, R2 with both Serial Interface to R1 and Ethernet Interface to the switched network, and two additional routers on the switched network – R3 & R4. This layout mirror the OSPF lab used by Jeremy Cioara on the OSPF part of the CBT Nuggets video.

Step I:
This step is identical to my EIGRP lab: configuring all the interfaces as the diagram show. For the exam it is always good to remember that a no shutdown is required on every interface. Always assume that an interface is administratively down.

Step II:
Once again (and here it ends) similar action: completing the interfaces configuration I used ping to test the connections (I test every connection, one ping per interface).
When I was sure that all the connections are working it was time to start OSPF on all the routers using the following commands:
router ospf 1
network 10.1.14.0 0.0.0.3 area 0

network 172.30.49.0 0.0.0.255 area 0
->Area 0 is the backbone
network 172.30.50.0 0.0.0.255 area 0 ->Network uses wild card mask

This is a sample of the output on R1 when both Serial Interfaces came up

*Mar  1 00:17:51.035: %LINK-3-UPDOWN: Interface Serial0/0, changed state to up
*Mar  1 00:17:54.043: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0,
changed state to up
*Mar  1 00:18:11.451: %OSPF-5-ADJCHG: Process 1, Nbr 172.30.50.2 on Serial0/0 fr
om LOADING to FULL, Loading Done

This a sample from R2 at the same time

*Mar  1 00:18:01.215: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0,
changed state to up
*Mar  1 00:18:11.095: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.14.1 on Serial0/0 fr
om LOADING to FULL, Loading Done

Step III
Running show commands to verify OSPF is running and neighbors can communicate.
These are the outputs from R1:

R1#sh ip ospf neighbor

Neighbor ID     Pri   State Dead Time   Address         Interface
172.30.50.2       0   FULL/  –        00:00:38    10.1.14.2       Serial0/0

R1#sh ip ospf
Routing Process “ospf 1” with ID 10.1.14.1
Supports only single TOS(TOS0) routes
Supports opaque LSA
Supports Link-local Signaling (LLS)
Supports area transit capability
Initial SPF schedule delay 5000 msecs
Minimum hold time between two consecutive SPFs 10000 msecs
Maximum wait time between two consecutive SPFs 10000 msecs
Incremental-SPF disabled
Minimum LSA interval 5 secs
Minimum LSA arrival 1000 msecs
LSA group pacing timer 240 secs
Interface flood pacing timer 33 msecs
Retransmission pacing timer 66 msecs
Number of external LSA 0. Checksum Sum 0x000000
Number of opaque AS LSA 0. Checksum Sum 0x000000
Number of DCbitless external and opaque AS LSA 0
Number of DoNotAge external and opaque AS LSA 0
Number of areas in this router is 1. 1 normal 0 stub 0 nssa
Number of areas transit capable is 0
External flood list length 0
Area BACKBONE(0)
Number of interfaces in this area is 2 (1 loopback)
Area has no authentication
SPF algorithm last executed 00:05:38.504 ago
SPF algorithm executed 3 times
Area ranges are
Number of LSA 2. Checksum Sum 0x011D6A
Number of opaque link LSA 0. Checksum Sum 0x000000
Number of DCbitless LSA 0
Number of indication LSA 0
Number of DoNotAge LSA 0
Flood list length 0

R1#sh ip ospf interface
Loopback1 is up, line protocol is up
Internet Address 172.30.49.1/24, Area 0
Process ID 1, Router ID 10.1.14.1, Network Type LOOPBACK, Cost: 1
Loopback interface is treated as a stub Host
Serial0/0 is up, line protocol is up
Internet Address 10.1.14.1/30, Area 0
Process ID 1, Router ID 10.1.14.1, Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:08
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 172.30.50.2
Suppress hello for 0 neighbor(s)

R1#show ip ospf database

OSPF Router with ID (10.1.14.1) (Process ID 1)

Router Link States (Area 0)

Link ID         ADV Router      Age         Seq#       Checksum Link count
10.1.14.1       10.1.14.1       339         0x80000004 0x00E649 3
172.30.50.2     172.30.50.2     582         0x80000004 0x003721 2

The outputs on R2 are similar, I’ll just show the neighbor:

R2#sh ip ospf neighbor

Neighbor ID     Pri   State           Dead Time   Address         Interface
10.1.14.1         0   FULL/  –        00:00:35    10.1.14.1       Serial0/0

At this point OSPF is working and neighbors are communicating. You can check the configuration files of R1 and R2 (R3 & R4 have similar config).

Step IV:

Time to play with the routers. In order to see how the routers react to failure of a neighbor I turned off S0/0 on R1. These are the errors on R1:

*Mar  1 00:16:00.419: %OSPF-5-ADJCHG: Process 1, Nbr 172.30.50.2 on Serial0/0 from FULL to DOWN, Neighbor Down: Interface down or detached
*Mar  1 00:16:02.387: %LINK-5-CHANGED: Interface Serial0/0, changed state to administratively down
*Mar  1 00:16:03.387: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to down

And on R2

*Mar  1 00:16:41.239: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.14.1 on Serial0/0 from FULL to DOWN, Neighbor Down: Interface down or detached
*Mar  1 00:16:41.251: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to down

Fixing the problem (no shutdown command) prompted the following on R1:

*Mar  1 00:17:51.035: %LINK-3-UPDOWN: Interface Serial0/0, changed state to up
*Mar  1 00:17:54.043: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
*Mar  1 00:18:11.451: %OSPF-5-ADJCHG: Process 1, Nbr 172.30.50.2 on Serial0/0 from LOADING to FULL, Loading Done

And on R2:

*Mar  1 00:18:01.215: %LINEPROTO-5-UPDOWN: Line protocol on Interface Serial0/0, changed state to up
*Mar  1 00:18:11.095: %OSPF-5-ADJCHG: Process 1, Nbr 10.1.14.1 on Serial0/0 from LOADING to FULL, Loading Done

Step V:

The last piece of the basic configuration is manual configuration of Router ID.
The command layout is:
router ospf 1
router-id 2.2.2.2
->2.2.2.2 is the manually assigned Router ID. It is not a network
The router is generous and we get the following warning:

R1(config)#router ospf 1
R1(config-router)#router-id 2.2.2.2
Reload or use “clear ip ospf process” command, for this to take effect

There are two ways to get the new ID actually working: The clear command or reloading the router. In most cases we would use the clear command and avoid the reload.
2 points to pay attention to:
clear ip ospf process command run from global exec mode but not on the interface
When you apply the clear command the neighbor status will go down and on a production router you should make sure you can take the network down.

The result of the new Router ID is

R1#sh ip ospf int
Loopback1 is up, line protocol is up
Internet Address 172.30.49.1/24, Area 0
Process ID 1, Router ID 2.2.2.2, Network Type LOOPBACK, Cost: 1
Loopback interface is treated as a stub Host
Serial0/0 is up, line protocol is up
Internet Address 10.1.14.1/30, Area 0
Process ID 1, Router ID 2.2.2.2, Network Type POINT_TO_POINT, Cost: 64
Transmit Delay is 1 sec, State POINT_TO_POINT,
Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5
oob-resync timeout 40
Hello due in 00:00:05
Supports Link-local Signaling (LLS)
Index 1/1, flood queue length 0
Next 0x0(0)/0x0(0)
Last flood scan length is 1, maximum is 1
Last flood scan time is 0 msec, maximum is 0 msec
Neighbor Count is 1, Adjacent neighbor count is 1
Adjacent with neighbor 172.30.50.2
Suppress hello for 0 neighbor(s)

This is the basic OSPF and even if it doe look complicated, it is not.
Now it’s time to dive in and start mixing it up with some complicated concepts and designs!

Find more labs here

Advertisements
  1. netscen
    February 11, 2010 at 3:34 am

    Yeah, it’s been a project a while now, and we finally managed to find the time for it as well.

    I’ve read your EIGRP lab a few days ago and I’ve done some similar fiddling, but at that point there’s not much advanced stuff you can do. The real fun starts after OSPF and redistribution. And ends when you hit multicast and IPv6. 😀

  2. Rofi Neron
    February 10, 2010 at 11:11 pm

    thanks Chris, there is more to come in the coming days as I move forward with OSPF
    you can use my EIGRP lab for BSCI and soon I’ll post my study notes
    I saw that you just started the blog so good luck and I guess I’ll see you around here in the coming weeks 🙂

  3. netscen
    February 10, 2010 at 3:37 pm

    Hey Rofi,

    If you want a more complex design, I’ve just started a monster OSPF lab on http://www.net-scenarios.net (where I’m coauthoring with a friend) that I’m using for my BSCI study.
    I just bumped into your blog a few days ago. I like your posts and I thought ours might be of some use.

    Cheers,
    Chris

  1. No trackbacks yet.

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s

%d bloggers like this: