kindly add video for this lab as i am so interested in it 
BGP Attribute Origin
Scenario:
You are a gunslinger living in Arizona and also a network engineer for the town network. To make sure your town has connectivity with other towns you have configured the town router with BGP. Another town is using AS 1 and they are advertising a network to you. Unfortunately they have misconfigured their network so you are sending traffic to the wrong router. Your own router is an old model from 1873 and doesn't allow many changes...let's see if you can configure AS 1 to solve your problem.
Goal:
- All IP addresses have been preconfigured for you as specified in the topology picture.
- Configure EBGP between router Lonergan and Colorado.
- Configure EBGP between router Claiborne and Colorado.
- Advertise the 13.13.13.0 /24 network on router Lonergan and Claiborne.
- Make sure router Colorado sends traffic to 13.13.13.0 /24 to router Claiborne, you are only allowed to use the origin attribute.
IOS:
c3640-jk9o3s-mz.124-16.bin
Topology:
Video Solution:
You need to register to download the GNS3 Topology File. (Registration is Free!)
- Related Articles
Only registered users can write comments!
Comments (11)
-
jarisaizprua 2011-08-29 18:37:31Done,
* Lonergan advertises the network 13.13.13.0/24 using the command "redistribute" so the attribute ORIGIN is INCOMPLETE.
* Claiborne advertises the network 13.13.13.0/24 using the command "network" so the attribute ORIGIN is IGP.
* As we know about ORIGIN, IGP is prefered over INCOMPLETE; pleae check the next BGP tables:
COLORADO#show ip bgp
BGP table version is 8, local router ID is 192.168.23.1
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path
*> 13.13.13.0/24 192.168.23.2 0 0 1 i
* 192.168.12.2 0 0 1 ?COLORADO#show ip bgp 13.13.13.0/24
BGP routing table entry for 13.13.13.0/24, version 8
Paths: (2 available, best #1, table Default-IP-Routing-Table)
Flag: 0x820
Advertised to update-groups:
1
1
192.168.23.2 from 192.168.23.2 (13.13.13.1)
Origin IGP, metric 0, localpref 100, valid, external, best
1
192.168.12.2 from 192.168.12.2 (13.13.13.1)
Origin incomplete, metric 0, localpref 100, valid, external
-
ReneMolenaar 2011-08-31 11:16:16Quote:As we know about ORIGIN, IGP is prefered over INCOMPLETE.This is the correct way to solve this lab. Will upload the video asap.
-
angipp01 2011-09-01 05:25:07I am sorry Jaris your way works but the lab does not tell to redistribute the network into BGP.
The Key to this lab is to use the origin command.
router bgp 2
no synchronization
bgp log-neighbor-changes
neighbor 192.168.12.1 remote-as 1
neighbor 192.168.12.1 route-map pass in
neighbor 192.168.23.3 remote-as 1
neighbor 192.168.23.3 route-map test in
no auto-summaryip forward-protocol nd
access-list 1 permit 13.13.13.0 0.0.0.255route-map pass permit 10
match ip address 1
set origin egp 1route-map pass permit 20
route-map test permit 10
match ip address 1
set origin igproute-map test permit 20
Yes the "test" was over board.
Jarvis was correct "As we know about ORIGIN, IGP is prefered over INCOMPLETE; pleae check the next BGP tables:"Again the concept to this lab was to use the "origin"
-
angipp01 2011-09-01 05:25:50
Colorado#sh ip bgp
BGP table version is 2, local router ID is 192.168.23.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path
* 13.13.13.0/24 192.168.12.1 0 0 1 e
*> 192.168.23.3 0 0 1 i
-
jarisaizprua 2011-09-01 19:14:29
Hi Angelo, your way also works, but in the goals list there's any rule about using ORIGIN/REDISTRIBUTE/NETWORK commands, so each person can solve this lab using different ways; you have yours, I have mine and the others will have theirs.
Anyway why did you choose the parameter EGP instead of INCOMPLETE??? You should know that BGP replaced to EGP many years ago therefore the EGP parameter into the ORIGIN attribute is deprecated.
The author is the only person whose should choose the best solution because he already has the answer.
Regards my friend!!!
-
angipp01 2011-09-03 15:29:32
Hello Jarvis
"Anyway why did you choose the parameter EGP instead of INCOMPLETE??? You should know that BGP replaced to EGP many years ago therefore the EGP parameter into the ORIGIN attribute is deprecated."Your correct with EGP that it is no longer used. I just wanted to apply it to a route-map but it always chose 192.169.12.0 network. I did understand why. So I used 'set orgin egp' and it then the best path moved to 192.168.23.0 network. Next time I am going to do it your way.
I wonder if I did this on the exam if I was wrong?
Anyways thanks.
Angelo
-
ReneMolenaar 2011-09-05 16:32:03
Hello Angelo & Jaris,
You are both correct with your solution. BGP will prefer IGP over incomplete routes so that's how you can influence which next-hop the router will choose.
The redistribute command will make a network show up as incomplete, the network command will make it show up as IGP.
Origin Code (IGP < EGP < Incomplete)
There is more than one way that leads to rome ;D good job though guys!
Rene
-
ashraf 2012-04-07 14:14:21allow-as in
-
farhand1@gmail.com 2012-04-09 21:53:29I solved the lab same way as Angelo did. The only comment i wanna make is we don't need two route-maps one is good enough because by default both routers Lonergan and claiborne advertising a 13 network with origin of igp so we just need to set ORIGIN incomplete for route coming from LONERGAN router.
Colorado#sh ip bgp
BGP table version is 4, local router ID is 192.168.23.2
Status codes: s suppressed, d damped, h history, * valid, > best, i - internal,
r RIB-failure, S Stale
Origin codes: i - IGP, e - EGP, ? - incompleteNetwork Next Hop Metric LocPrf Weight Path
*> 13.13.13.0/24 192.168.23.3 0 0 1 i
* 192.168.12.1 0 0 1 ?
-
ReneMolenaar 2012-04-10 08:23:41
Seems like you got it
good job!