From: Scott Morris (smorris@internetworkexpert.com)
Date: Sun Aug 03 2008 - 16:27:56 ART
The requirements within OSPFv2 are that all LSAs must traverse Area 0. All
packets do not need to. All calculations FIRST are targeted through area 0,
then ABRs look at Intra-Area connections to other ABRs and see whether or
not they have a "shortcut" for more optimal packet movement.
So you may actually find different results given different topologies which
can be VERY frustrating! :)
Scott
-----Original Message-----
From: Joseph Brunner [mailto:joe@affirmedsystems.com]
Sent: Sunday, August 03, 2008 2:12 PM
To: smorris@internetworkexpert.com; 'dave dave'; 'Cisco certification';
bdennis@internetworkexpert.com; blog@internetworkexpert.com
Subject: RE: EXPERT plz plz help...OSPF scnario brusting my head..
What of the requirement that traffic flow through area 0 between 2 non-zero
areas... I have seen this trump all in my rack many times!
-----Original Message-----
From: Scott Morris [mailto:smorris@internetworkexpert.com]
Sent: Sunday, August 03, 2008 1:57 PM
To: 'dave dave'; 'Cisco certification'; bdennis@internetworkexpert.com;
blog@internetworkexpert.com; 'Joseph Brunner'
Subject: RE: EXPERT plz plz help...OSPF scnario brusting my head..
Intra Area will always come first.
Inter Area next.
External third. Within the externals, you'll prefer a Type1 (N1/E1) over a
Type 2.
HTH,
Scott Morris, CCIE4 #4713, JNCIE-M #153, JNCIS-ER, CISSP, et al.
CCSI/JNCI-M/JNCI-ER
Senior CCIE Instructor
smorris@internetworkexpert.com
Internetwork Expert, Inc.
http://www.InternetworkExpert.com
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Knowledge is power.
Power corrupts.
Study hard and be Eeeeviiiil......
-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of dave
dave
Sent: Sunday, August 03, 2008 11:28 AM
To: Cisco certification; bdennis@internetworkexpert.com;
blog@internetworkexpert.com; Joseph Brunner
Subject: Re: EXPERT plz plz help...OSPF scnario brusting my head..
Hi All,
Thanks for your help. You was right as usual Mr. Brian :-)
Thanks all who took effort to help me.
One more Question: what is OSPF route selection order in term of intra,
inter, n1, n2, e1& e2 ?
r6#sh ip route 200.1.1.1
Routing entry for 200.1.1.0/24
Known via "ospf 1", distance 110, metric 301, *type inter area
* Last update from 10.66.2.1 on FastEthernet1/11, 00:33:09 ago
Routing Descriptor Blocks:
* 10.66.2.10, from 10.66.2.10, 00:33:09 ago, via FastEthernet1/10
Route metric is 301, traffic share count is 1
10.66.2.1, from 10.66.2.6, 00:33:09 ago, via FastEthernet1/11
Route metric is 301, traffic share count is 1
r4#sh ip ro 200.1.1.1
Routing entry for 200.1.1.0/24
Known via "ospf 1", distance 110, metric 201, *type intra area
* Last update from 10.66.1.9 on FastEthernet1/11, 00:52:52 ago
Routing Descriptor Blocks:
* 10.66.1.9, from 200.1.1.1, 00:52:52 ago, via FastEthernet1/11
Route metric is 201, traffic share count is 1
Regards,
Dave
On 8/3/08, dave dave <funccie@gmail.com> wrote:
>
> Hi Expert,
>
> *net: 200.0.0.0/24*
> --------------------------
> | |
> *R1* ----------------* R2*
> | |
> *R3=========R4* << === it means 2 physical L2 links ether channel as
> e.g. L2 Po1 & Vlan 100 running on R3 as well as R4 to to form ospf
> neighborship over L2 port channel. Vlan 100 in area 0
> | |
> *R5*----------------*R6*
> | |
> -------------------------
> *net: 100.0.0.0/24*
>
> Note :
> this color represting the ospf area 2
> this color represting the ospf area 1 this color represting the ospf
> area 0
>
> 1) R1, R2 & including links of R1 & R2 connected to R3 & R4 are on
> OSPF area 1
> 2) R5, R6 & including links of R5 & R6 connected to R3 & R4 are on
> OSPF area 2
> 3) All links are 100 Mbps.
> 4) L2 ether channel of each 100 Mbps links between the R3 & R4 is for
> vlan 100 ospf neighborship
> 5.) when i am traceroute from R6 to R1 for 200.x.x.x it is taking the
> path as follow:
> R6 --> R4 --> R2 --> R1-->200.x.x.x i am expecting the path as
> below , thinking it is the best path to reach destination.
> R6 --> R4 --> R3 --> R1-->200.x.x.x
>
> Regards,
> Dave
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