MPLS VPN Lab - All you need to know for CCIE R&S (Coming this weekend)

Difference Between Routing Table & RIB (Routing Information Base) - Short Post

It's been long time since I wanted to talk over my blog about this. I have seen many people and books claiming that RIB is just another name of I should say fancy term to describe our old friend Routing Table. But In my personal opinion there is a significant difference between both.


RIB or Routing Information Base is local view about information from Routing Protocol Prospective. For example each routing protocol including BGP generates BGPtables in General. Yeah I know there are some more details as far how BGP builds its BGP Table :-). But for now lets talk about BGP table in short.


BGP table is local view of routing information received and generated locally. If you have ever run BGP than you must be aware about situations where you find some routing information which is in BGP table but when you run "show ip route" command , you don't see this information there. 


There are many possible reason for that in BGP like "Un-Reachable Next Hop" Address.


So what actually we see with "show ip bgp" is RIB built by BGP. On the other hand what we see with "show ip route" is Routing table which is derived from that RIB information. Or in other words best and valid information picked by router from BGP Table and placed it into routing table.

so next idea comes into mind is that how we check RIB for each protocol ?


And here is answer :-)


RIP -  "sh ip rip database"


OSPF - Older way > "sh ip ospf database"
              Modern Way > "sh ip ospf rib detail"


EIGRP - "sh ip eigrp topology all-links"


BGP - "sh ip bgp"


IS-IS - "sh isis database"


With the "sh ip eigrp topology all-links" command you can actually see routes that failed the feasibility check.


Also one of the reason that support idea of RIB being different from Routing Table is - In OSPF for example if Forwarding Address (FA) for LSA 5 is not reachable, in such case you will see entries for those LSAs in "OSPF database" with command " sh ip ospf database" but on the other hand you won't find those routes in Routing table when you run command "sh ip route"


HTH...
Deepak Arora 

OSPF Mock Lab 1 - Finally Out

Click Image To Enlarge

As I promised earlier, Finally the I am proud to announce about release of OSPF Mock Lab-1 & Trust me it's not going to be easy one :-)

But on the other hand I won't be able to work on any more Protocol Based Mock lab until I pass my R&S Lab which is scheduled for April End 2011. Reason being is that developing such material takes significant time. The OSPF mock lab was supposed to come out in two parts with around 25-30 Tasks each. But you guys must wait for OSPF Mock Lab 2 now. 

But still I am trying my best to bring entertainment for all readers in terms of learning.

With that being said, here is quick link for downloading list of tasks file. Again I would suggest to use Foxit Acrobat reader incase you guys can't see it properly in Adobe Acrobat reader. The password for PDF file is again - deepakarora

http://www.4shared.com/document/aMZ5tu_-/OSPF_Mock_Lab_1_-_List_of_Task.html 

Logical topology you can see above. For GNS physical topology refer the diagram:

https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiKPI1WpViLsaY4fnQLtJLbx-85B5G2cwEEGPP5_YF2J-6Wak-C1ksZtSabWH0eK3CmV4Iqm7wVRnSoYBIP4nR6zYXIJx5MfCqdSJ_wu142sQR7SotHN8E39_aCHDVpumwxcJfgY9cnOyY/s1600/OSPF+Mock+Lab+Topology.png

Here is the quick link to download initial configuration file that you would need for each router. Also I added some troubleshooting. So watch out for that :-)

As your OSPF peerings may not come up easily. For getting solution for any of tasks send me an email at - deepakarora.1984@gmail.com with your comments about Blog and Mock Labs.

http://www.4shared.com/document/Oxt5Zp_2/OSPF_Mock_Lab_Initials.html

HTH...
Deepak Arora 

Meet the First Two Cisco Certified Architects - CCA

http://www.youtube.com/watch?v=ZHmodEzkbH8&feature=related

http://www.youtube.com/watch?v=eZeEzBK-AcI&feature=related

http://www.youtube.com/watch?v=YfTjS7BxHzQ&feature=player_embedded

HTH...

Deepak Arora

How Many Types of ACLs are there in Cisco's Big IOS Security World

Few days back I asked a question to a very confident CCNA Security guy...actually he just came to me before taking CCNA Security exam and asked me...hey,why don't you ask me something related to Security as I am feeling pretty confident that I know lots of security stuff now.

Hmmm...I said Okey and just asked him the following question :-)

How many ACLs and Firewall features we have in IOS related to Router Security ?

He said... Standard ACL, Extended ACL, Named ACL, Reflexive ACL, CBAC & Zone Based Firewall.

Hmmm...his list looks interesting but still not complete...maybe it was not a true CCNA Security Question as I never take a look at it's curriculum...Anyways...Following is my list and see if I missed something...Feel free to drop an email to me if you have something to add in this list.

1. Standard ACL
2. Extended ACL
3. Named ACL
4. TCP Established ACL / Reflexive ACL
5. Turbo ACL
6. CBAC
7. Zone Based Firewall
8. Time Based ACL
9. Dynamic ACL / Lock & Key ACL
10. Flexibal Packet Matching ACL
11. ACL to to prevent fragmented IP packets from reaching you application ports

Holy Cow...Did you ever think about that :-(

I must say even I still need to dig myself about which one takes precedence over other when multiple types are configured together

Some more ACL stuff in coming days along with solution of my last ACL Post...

Happy Studying...

Best Regards,
Deepak Arora
CCIE# XXXXX...Oops that number is still missing :-)

Cisco Certified Architect

Cisco Certified Architect is highest level of accreditation achievable within the Cisco Career Certification program. It is the pinnacle for individuals wishing to show their formal validation of both design and IT skills in Cisco technologies and infrastructure.

Cisco Certified Architect Prerequisites

Valid CCDE certification

http://www.cisco.com/web/learning/le3/cisco_certified_architect/index.html