From: christopher snow (cbsnow31@yahoo.com)
Date: Tue Feb 24 2004 - 10:18:55 GMT-3
That is correct. The only protocol that behaves
differently is ISIS. ISIS will not advertise a
connected network unless told to do so. BGP does not
route per say like OSPF. It simply advertises
reachability and does not have a default behavior like
an interior routing protocol.
Chris
--- Karim <karim_ccie@hotmail.com> wrote:
> Hi all,
>
> From the posts that was sent about this issue from
> Michael, Chris and
> Alsontra, I can get the following but I need you to
> correct me if I am
> wrong:
> - When redistributing from RIP into OSPF, both the
> existing RIP routes in
> the routing table and connected interface with RIP
> network command will be
> redistributed into OSPF.
> - Whenever I add a redistribute connected with a
> route map to the OSPF
> process, this will stop redistributing the RIP
> connected interfaces into
> OSPF.
> - To have these interfaces (connected interfaces)
> redistributed again into
> OSPF, I have use redistribute connected and don't
> rely on the RIP into OSPF
> redistribution.
>
> I have seen this behavior with RIP to OSPF
> redistribution but does this
> behavior implies to the other way (OSPF to RIP) and
> will it be the same for
> all routing protocols (IGPs and BGP) ??
>
> Many thanks in advance for your help,
> Karim.
>
>
> ----- Original Message -----
> From: <alsontra@hotmail.com>
> To: "christopher snow" <cbsnow31@yahoo.com>
> Cc: <ccielab@groupstudy.com>
> Sent: Sunday, February 22, 2004 7:11 PM
> Subject: Re: Redistrbute Connected breaks other igp
> connected routes on the
> same router
>
>
> > Brilliant! I never would have figured that out on
> my own. So let me get
> > this straight, if your using the redistribute
> (protocol) command and you
> > start to specify individual interfaces you
> effectively remove all
> previously
> > specified interfaces. You are now doing manual
> distribution by virtue of
> > the fact that are explicitly pointing out
> individual interface using
> > route-maps?
> >
> >
> > Alsontra
> >
> > GroupStudy Rocks!
> >
> >
> > ----- Original Message -----
> > From: "christopher snow" <cbsnow31@yahoo.com>
> > To: <alsontra@hotmail.com>
> > Cc: <ccielab@groupstudy.com>
> > Sent: Sunday, February 22, 2004 2:25 AM
> > Subject: Re: Redistrbute Connected breaks other
> igp connected routes on
> the
> > same router
> >
> >
> > > Think about the default behavior of the router
> when
> > > you redistribute from one protocol into another.
> For
> > > instance, if one tells the router to
> redistribute rip
> > > into ospf the router will do two steps. First,
> it
> > > will take all the rip routes in the routing
> table
> > > (unless filtering). Second, it will take all of
> the
> > > interfaces that rip is running on by default.
> What
> > > happens later, and is somewhat of a trap, is
> that one
> > > may be told to redistribute a loopback address
> into
> > > OSPF later in the scenrio. When one does a
> > > redistribute connected under OSPF with a
> route-map
> > > that references the loopback, the default
> behavior
> > > (second step above) has now been manually
> overridden.
> > > By manually specifing the loopback address
> alone, one
> > > has now inadvertantly removed the
> interfaces/subnets
> > > that were once being used by default (second
> step
> > > above). You must now manually add those
> > > subnets/interfaces to the connected route-map.
> Lab it
> > > up and check it out :)
> > >
> > > HTH,
> > >
> > > Chris Snow
> > >
> > >
> > > --- alsontra@hotmail.com wrote:
> > > > Are you saying that ospf removed a connected
> > > > interface from its LSA database
> > > > when you used the redistribute connected
> command on
> > > > another interface?
> > > >
> > > > Alsontra
> > > >
> > > >
> > > > I noticed this behavior a few days ago, after
> the
> > > > fact. This time I
> > > > caught it red handed. What a nightmare in the
> lab
> > > > this could be.
> > > > Here's what I was doing, the local isis
> interface
> > > > didn't get
> > > > redistributed, which is normal.
> > > > I use tags, so I included the local interface
> (s0.24
> > > > 136.10.24.0/29)
> > > > with the proper tag for isis into ospf, fixing
> what
> > > > isis should have
> > > > done. (step 1)
> > > > Immediately my rip (s1 136.10.12.0/24)
> connected
> > > > route which was
> > > > perfectly stable dropped out of ospf. (step 2)
> > > > I did nothing to effect the redistribution
> between
> > > > rip and ospf! It has
> > > > to be some logic being turned off by a
> specific
> > > > redistribute connected
> > > > cmd being present in the ospf config.
> > > > To fix it, I added another statement to my
> route-map
> > > > using the right tag
> > > > for rip, and the route came back. (step 3)
> > > > Remote router watching ospf routes
> > > > Step 1) -
> > > > RT: add 136.10.24.0/29 via 136.10.56.5, ospf
> metric
> > > > [110/1065]
> > > > Step 2)
> > > > RT: del 136.10.12.0/24 via 136.10.56.5, ospf
> metric
> > > > [110/1065]
> > > > RT: delete subnet route to 136.10.12.0/24
> > > > Step 3)
> > > > RT: add 136.10.12.0/24 via 136.10.56.5, ospf
> metric
> > > > [110/1065]
> > > >
> > >
>
------------------------------------------------------------------------
> > > > ----
> > > > Step 1)
> > > > redistribute connected metric 1000 metric-type
> 1
> > > > subnets route-map
> > > > connectedisis
> > > > route-map connectedisis permit 10
> > > > match interface Serial0.24
> > > > set tag 444
> > > > Step 3)
> > > > route-map connectedisis permit 15
> > > > match interface Serial1
> > > > set tag 111
> > > >
> > >
>
------------------------------------------------------------------------
> > > > ----
> > > > Is this normal? Maybe a bug in my ios? I
> hadn't
> > > > noticed it before, but
> > > > I notice a lot more now than I used to.
> > > >
> > >
>
This archive was generated by hypermail 2.1.4 : Fri Mar 05 2004 - 07:13:56 GMT-3