From: Howard C. Berkowitz (hcb@gettcomm.com)
Date: Sun Jul 04 2004 - 18:49:36 GMT-3
At 4:35 PM -0700 7/4/04, <alsontra@hotmail.com> wrote:
>Yes, this is what I was asking. I would have thought that protocols
>redistributed information from their individual topology databases. The idea
>that redistributed information comes from the RIB is very new to me.
>However, it clearly explains why single device indirect redistribution is
>not possible.
>Just to be sure that I'm clear, the RIB takes the best (lowest admin
>distance, longest match, etc) routes from all protocols and it is from this
>information or database that mutual redistribution occurs.
Yes. Order of preference:
1. Completely new route: INSTALL
2. More specific of existing route: INSTALL
3. Lower administrative distance: REPLACE
Equal administrative distance
If STATIC INSTALL & LOAD BALANCE*
Else
If LOWER METRIC REPLACE
Else
if EQUAL METRIC INSTALL & LOAD BALANCE*
*up to maximum paths.
** BGP first checks its own Loc-RIB
>??? Simply put,
>the RIB's singular selection of "most preferable" routes can cause the lose
>of less preferable protocol information.
Yes. It's also a safety measure for loop prevention to only advertise
routes that the local router actually is using for forwarding.
>As I understand it, the solution to this problem is to mutual redistribute
>all protocols. ??? Correct?
Could you restate the problem? This is for lab practice, I assume --
in the real world, you want to redistribute as little as possible.
This archive was generated by hypermail 2.1.4 : Sun Aug 01 2004 - 10:11:46 GMT-3