From: Nodir Nazarov (nodir@xxxxxxxxxxxx)
Date: Mon Apr 30 2001 - 11:35:47 GMT-3
'
It will work predictable if you do mutual redistribution. If you do one
way only - I couldn't get it working either..
Nodir
On Mon, 30 Apr 2001, Russell Lusignan wrote:
> Hey Jim, I know the summary is for redistributing routing protocols into
> OSPF. I was wrestling with getting VLSM routes int IGRP. People in this
> list have mentioned before that you can use the summary-address to get the
> routes into IGRP also. This is what sparked this thread :) Unfortunately
> it never works/doesn't work the same way twice.
>
> > -----Original Message-----
> > From: jim.fitzpatrick@verizon.com [mailto:jim.fitzpatrick@verizon.com]
> > Sent: Monday, April 30, 2001 8:41 AM
> > To: ccielab@groupstudy.com
> > Subject: RE: OSPF summar-address into IGRP
> >
> >
> > I have just been reading this thread and it appears to me
> > that you may be
> > trying to use the OSPF 'summary-address' command in the wrong
> > context. This
> > command is for summarizing routes as they go IN to OSPF. If
> > you are trying to
> > summarize routes for redistribution this should be done on an
> > ABR not the
> > ASBR. To get the OSPF routes into IGRP summarize them to a
> > classfull boundary
> > on an ABR and then redistribute into IGRP on the ASBR.
> >
> > Jim
> > ---------- Original Text ----------
> >
> > From: "Mas Kato" <tealp729@home.com>, on 4/30/2001 2:00 AM:
> >
> > Russ,
> >
> > Thanks, I took it for granted that mutual redistribution was
> > part of the
> > deal. What's got me in stitches after reading about your findings is
> > I -couldn't- get it to work with my directly connected OSPF subnet.
> >
> > All my summary would ever look like is this one from your OSPF process
> > 200:
> >
> > 170.10.13.0/255.255.255.128 Metric 16777215, Type 0, Tag 0
> >
> > ...with that peculiar metric; The only difference being I was
> > trying to
> > summarize a directly-connected OSPF /28 route into an IGRP
> > /24 AS. 'show
> > ip protocols' would indicate that address summarization was
> > taking place
> > in my OSPF process, but the field that would indicate "for which
> > networks" would be blank.
> >
> > The only way I ever got the OSPF 'summary-address' command to work was
> > by employing it exactly as it is documented. I redistributed
> > a /30 from
> > an EIGRP AS on the other side of the network. One philosophy,
> > I'm told,
> > is to preserve the specificity of the route as long as possible, so I
> > tried to summarize the route at the OSPF/IGRP ASBR. Nope. I
> > had to place
> > the command exactly where the docs say to place it--at the ASBR
> > redistributing the route in.
> >
> > I've long since moved on to other topics, uneasily writing
> > this one off
> > as bug that may be exploited perhaps in earlier or different builds of
> > the IOS (I'm running 12.1(7)). I'm just going to have to find a way to
> > work-around it and defend my tactics if I get dealt a situation that
> > calls for it in the lab. My uneasiness has only grown after wrestling
> > with glitches in other areas as well--like the whole DDR mess,
> > NLSP-to-IPX EIGRP aggregate route redistribution, DLSW
> > filtering logic,
> > etc.--because of things like this, I'm grateful this group exists!!
> >
> > Mas
> >
> > -----Original Message-----
> > From: nobody@groupstudy.com [mailto:nobody@groupstudy.com]On Behalf Of
> > Russell Lusignan
> > Sent: Sunday, April 29, 2001 8:16 PM
> > To: 'ccielab@groupstudy.com'
> > Subject: RE: OSPF summar-address into IGRP
> >
> >
> > Mas,
> >
> > This one is worrying me quite a bit to.. I have done quite a bit of
> > fooling
> > around since I got it working.. Here is some of the stuff I have
> > figured
> > out. Feel free to make comments on it (everyone):
> >
> > - The summary-address command wasn't giving me null0 routes
> > in the ospf
> > routing table until I did a "redistribute.. " command in the ospf
> > process.
> > So basically, unless I did mutual redistribution between
> > ospf/igrp, the
> > summary-address trick of getting routes into IGRP didn't work.
> >
> > - It appeard that only directly connected subnets summarized by the
> > summary-address command on the ASBR were being redistributed
> > successfully
> > into IGRP, again only if mutual redist was configured.
> >
> > - So, mutual redistribute, what would happen if I did mutual
> > redistribution
> > between a separate OSPF process and IGRP? I added another
> > ospf process,
> > here
> > is the basic config:
> >
> > route ospf 100
> > router-id 170.12.1.1
> > area 0 authentication message-digest
> > network 170.10.1.0 0.0.0.255 area 0
> > network 170.10.12.0 0.0.0.15 area 0
> > !
> > router ospf 200
> > summary-address 170.10.24.0 255.255.255.128
> > summary-address 170.10.12.0 255.255.255.128
> > summary-address 170.10.13.0 255.255.255.128
> > summary-address 170.10.16.0 255.255.255.128
> > summary-address 170.10.17.0 255.255.255.128
> > summary-address 170.10.18.0 255.255.255.128
> > summary-address 170.10.19.0 255.255.255.128
> > summary-address 170.10.24.128 255.255.255.128
> > redist ospf 100 subnets
> > passive-interface ethernet0
> > passive-interface serial0
> > !
> > router igrp 50
> > redistribute ospf 200
> > network 170.10.0.0
> > default-metric 10000 1000 255 1 1500
> >
> > The idea behind this config is to redistribute routes learned through
> > OSPF
> > 100 into OSPF 200. OSPF 200 summarizes all of the routes to /25 which
> > is
> > the mask used on the IGRP interfaces. Now, from everything I
> > have read
> > in
> > the list and on Cisco's site and talked about with others, the
> > summary-addresses should summarize all of the routes learned from OSPF
> > 100
> > into /25 which should then redistribute succesfully into IGRP. Only 4
> > of
> > the routes summarized appeared in IGRP, so I figured that it must be a
> > metric/metric-type thing.. maybe that only inter-area routes
> > were being
> > successfully redistributed into IGRP, so I checked the summary-address
> > table
> > on ospf process 200.. Here is what it looked like:
> >
> > R1#sh ip ospf 200 summary-address
> >
> > OSPF Process 200, Summary-address
> >
> > 170.10.24.0/255.255.255.128 Metric 138, Type 2, Tag 0
> > 170.10.12.0/255.255.255.128 Metric 20, Type 2, Tag 0
> > 170.10.13.0/255.255.255.128 Metric 16777215, Type 0, Tag 0
> > 170.10.16.0/255.255.255.128 Metric 148, Type 2, Tag 0
> > 170.10.17.0/255.255.255.128 Metric 148, Type 2, Tag 0
> > 170.10.18.0/255.255.255.128 Metric 148, Type 2, Tag 0
> > 170.10.19.0/255.255.255.128 Metric 148, Type 2, Tag 0
> > 170.10.24.128/255.255.255.128 Metric 129, Type 2, Tag 0
> >
> > The freaky thing is that only 170.10.24.0/25, 170.10.24.128/25, and
> > 170.10.12.0/25 appeared in the IGRP routing table on R8. I
> > can't figure
> > out
> > what the common thing is with only those routes.
> >
> > I have tried this many ways.. not once have I felt comfortable that
> > this
> > will work if I do it from scratch, or if I reboot the router. So
> > basically
> > if I get this sort of problem in my lab (which I probably
> > will), I will
> > cross my fingers and hope it works.
> >
> > There is no technical explanation that I can find or make
> > that explains
> > the
> > behaviour of IGRP. And the kicker is, if I just add null0
> > routes on the
> > ASBR with a /25 mask it redistributes no problem. I hate IGRP.
> >
> > -Russ
> >
> > > -----Original Message-----
> > > From: Mas Kato [mailto:tealp729@home.com]
> > > Sent: Sunday, April 29, 2001 9:07 PM
> > > To: 'Russell Lusignan'; ccielab@groupstudy.com
> > > Subject: RE: OSPF summar-address into IGRP
> > >
> > >
> > > Russ,
> > >
> > > Allow me to kick the corpse a little... I have not been able
> > > to get this
> > > scenario to work, at least with 12.x. I could never get a
> > > null0 route to
> > > install on its own when the summary's major network was the
> > same as my
> > > OSPF network and where its mask matched my interface leading out of
> > > OSPF. 'show ip ospf summary' would show the summary with a very high
> > > metric--apparently unreachable.
> > >
> > > I'm sure your research has revealed that the documentation doesn't
> > > support this scenario and that the, uh, "official" way to do
> > > this is to
> > > either install a static summary route to null0 or source a default
> > > route.
> > >
> > > I'm so concerned with the possibility of having to defend situations
> > > like this during the lab exam, I recently wrote to the CCIE program
> > > about it. I asked point blank whether we could be asked to exploit
> > > undocumented "features" of IOS behavior. We all know how porous the
> > > documentation is--we'll see...
> > >
> > > So how on Earth did you finally get it to work? Does it
> > > survive reboots
> > > and such?
> > >
> > > Regards,
> > >
> > > Mas Kato
> > >
> > >
> > > -----Original Message-----
> > > From: nobody@groupstudy.com
> > [mailto:nobody@groupstudy.com]On Behalf Of
> > > Russell Lusignan
> > > Sent: Sunday, April 29, 2001 3:48 PM
> > > To: 'ccielab@groupstudy.com'
> > > Subject: RE: OSPF summar-address into IGRP
> > >
> > >
> > > Ummm... I spent a few days trying to figure this one out
> > to no avail,
> > > as
> > > soon as I post to this list my problem, it works. So, by adding the
> > > "summary-address 170.10.12.0 255.255.255.128" to R1, that subnet now
> > > shows
> > > up on R8. Weird. So for anyone reading my previous post about this
> > > problem, don't worry about it :)
> > >
> > > Too bad we don't have the ability to post to this list
> > while doing the
> > > actual lab :)
> > >
> > > sorry
> > > -Russ
> > >
> > >
> > >
> > > > -----Original Message-----
> > > > From: Russell Lusignan [mailto:rlusignan@birdonawire.com]
> > > > Sent: Sunday, April 29, 2001 5:08 PM
> > > > To: 'ccielab@groupstudy.com'
> > > > Subject: OSPF summar-address into IGRP
> > > >
> > > >
> > > > Hey group,
> > > >
> > > > This topic has been beaten to death, but I haven't be able to
> > > > find anything
> > > > in the archives on what is happening.
> > > >
> > > > OSPF IGRP
> > > > ------------------R1-------------------R8
> > > > 170.10.12.0/28 170.10.20.0/25
> > > >
> > > > I want the /28 to redistribute into IGRP, I know R1 won't
> > > advertise it
> > > > because it's not a /25. I have ready many posts about
> > > people using a
> > > > summary-address on R1 to summarize the /28 into a /25. This
> > > > does not work
> > > > for me. On R1, if I do "summary-address 170.10.12.0
> > > 255.255.255.128"
> > > > shouldn't that be enough to get that /28 into IGRP as a /25?
> > > > This works if
> > > > I place a null0 route on R1 with a /25 manually, and I have
> > > > managed to get a
> > > > default-network to R8, but if these are not permitted on the
> > > > lab, I am not
> > > > sure how else to do it.
> > > >
> > > > I recall reading a post a while back where someone mentioned
> > > > that when you
> > > > create a summary-address in ospf it should automatically
> > > > create a null0
> > > > route to that subnet, I know EIGRP does this, but wasn't
> > > > aware that ospf did
> > > > it. When I do create a summary-address there is no null0
> > > > route created with
> > > > OSPF...
> > > >
> > > > -Russ
> > > > **Please read:http://www.groupstudy.com/list/posting.html
> > > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> > **Please read:http://www.groupstudy.com/list/posting.html
> **Please read:http://www.groupstudy.com/list/posting.html
**Please read:http://www.groupstudy.com/list/posting.html
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