Re: OSPF default route multiple processes

Hey Marc, I would like to take a stab at your questions, but will let some
of the CCIEs with more experience confirm. I would expect the following to
take place:

Although there are two ospf processes running, there's only one routing
table. I would not expect ospf to treat its rules on route selection
differently. (this is an assumption). For true segmentation, consider vrfs.

As you mentioned, the type-1 LSA to be preferred over a type-2 LSA. Once
you make the default routes both of the same type, the following selection
criteria will apply:

   - If type-2 metric is the same, prefer route with better internal cost.
   - Directly from RFC: In any case, among the remaining routing table
   entries, select the routing table entry with the least cost; when there are
   multiple least cost routing table entries the entry whose associated area
   has the largest OSPF Area ID (when considered as an unsigned 32-bit
   integer) is chosen.

Best Regards,

Kristian J. Francisco

On Fri, Jul 26, 2013 at 10:20 AM, Marc La Porte <marc.a.laporte_at_gmail.com>wrote:

> Rati,
>
> How does it choose between the two processes though?
>
> Cheers,
> Marc
>
> On Fri, Jul 26, 2013 at 7:12 PM, Rati Berikaant Jokhadze
> <iinfo83_at_gmail.com>wrote:
>
> >
> > On 07/26/2013 08:50 PM, Marc La Porte wrote:
> >
> >> 1. What is the order of operation within OSPF to select default routes
> >> from
> >> different processes?
> >>
> >> 2. How do I ensure the border router ALWAYS takes the default route from
> >> Area 51 (although it has multiple default routes from Area 0 in it's
> >> database)? Since OSPF metric-type 1 has preference over metric-type 2,
> do
> >> I
> >> change the metric-type in Area 51 to type 2 and ensure it's always lower
> >> than from Area 0?
> >>
> > 1. First recieved route within process
> >
> > 2. I dont think so , that you can do this , someone will answer
> exactly...
>
>
> Blogs and organic groups at http://www.ccie.net
>
> _______________________________________________________________________
> Subscription information may be found at:
> http://www.groupstudy.com/list/CCIELab.html

Blogs and organic groups at http://www.ccie.net
Received on Fri Jul 26 2013 - 10:24:02 ART