From: Robert Rech (rjrech@xxxxxxxxxxxx)
Date: Wed Jul 31 2002 - 17:39:32 GMT-3
I believe if you are redistributing the ospf routes on both routers if
you put a network statement on R2 for the specific network. The origin
will be EGP vs incomplete for a route that was redistributed. If the
following are equal weight, local pref, origanted locally, AS-PATH. Then
the next criteria is as follows:
lowest origin where IGP is lower then EGP and EGP is lower then
IMCOMPLETE.
Redistributed routes have an origin or imcomplete.
Robert Rech
Senior Network Engineer
Cap Gemini Ernst & Young
Kansas City Service Center
rjrech@cgeykcsc.com
phone (816) 459-4767
fax (816) 459-6767
>>> Carlos G Mendioroz <tron@huapi.ba.ar> 07/30/02 02:36PM >>>
Chang,
go to the list of BGP route selection process and start thinking
"can I modify this ?"
I would go with the longest match: depending on your current setup,
this could be just advertising R3-R5 at R2 (if you are summarising,
that would work) or as a last resort, you could advertise all the
corresponding /32's. Not nice at all, but it plays along the rules...
ying c wrote:
>
> Hi,
>
> Here's one of the question that I wonder one of you
> smart guys may have an answer:
>
> R1------R2-------R3
> \ | |
> \-----R4-------R5
>
> R1 is in AS100, R2 and R4 are in AS200, R1, R2, R4 are
> running BGP. R2, R4, R3 and R4 are running OSPF. R2
> and R4 both peer with R1 and send full ospf specific
> routes to R1.
>
> The requirement is to have R1 always use R1-R2 link as
> the primary route to reach the network between R3 and
> R5. Normally, we would use MED, AS-PATH or aggregate
> routes to achieve this. However, here's the tricky
> part: you are not allowed to use MEDs and not to
> change the configuration on R1 or R4 to accomplish
> this.
>
> I did it by using a lower metric number when I
> redistribute ospf into bgp in R3, but I think this
> pretty much violated "not to use MEDs" rule. Is there
> any other way to solve it?
>
> Thanks,
> Chang
>
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