From: David Luu (wicked01@xxxxxxxxxxxxx)
Date: Sun May 19 2002 - 16:43:27 GMT-3
i may be the one with the bugged IOS since others aren't able to summarize
outgoing without the 2nd ospf process..im running an old 11.something IOS
At 09:34 AM 5/19/2002 -0400, Ludwig A. Morales wrote:
>Unless all my router has bugs on the IOS the summary address command *DOES
>NOTHING* to summarize outgoing advertisements, if any one have a working
>config with these pleases post it to prove-test this.
>
>Now, how would I use a second ospf process? do I create a second process
>and redistribute my original ospf, use summary address here and redistribute
>this one to igrp, or do I run the network I want to summarize in a second
>process, summarize it under my original process. please post an example if
>anyone have it.
>
>
>Regards,
>
>Ludwig----- Original Message -----
>From: "David Luu" <wicked01@ix.netcom.com>
>To: "Jonathan Hays" <jhays@jtan.com>; <ccielab@groupstudy.com>
>Sent: Sunday, May 19, 2002 3:50 AM
>Subject: RE: FATKID 502 Expert Redistribution
>
>
> > i did some testing out of curiosity, and the summary-address will be
> > advertised out of ospf with or without the 2nd ospf process...so i retract
> > the statement below...however i couldnt get it to ping across, buts its
> > probably some human error on my end...i will do some more testing to get
> > the ping to work...
> >
> > learning something new everyday
> >
> > At 11:51 PM 5/18/2002 -0700, David Luu wrote:
> > >summary-address summarizes going into ospf, not out
> > >
> > >if you looked at his config, the 135.1.20.0/22 subnet originated in ospf,
> > >so the summary-address would not be advertised to igrp
> > >
> > >since R4 is an ASBR, you need to summarize to a /24 by creating a second
> > >ospf process and redistributing it into and using the summary-address
> > >command on the first process
> > >
> > >
> > >At 11:13 PM 5/18/2002 -0700, Jonathan Hays wrote:
> > >>Yes - I know what you are thinking - this:
> > >>
> > >>http://www.cisco.com/warp/public/104/3.html#12.0
> > >>
> > >>"External Route Summarization
> > >>
> > >>External route summarization is specific to external routes that are
> > >>injected into OSPF via redistribution. Also, make sure that external
> > >>ranges that are being summarized are contiguous. Summarization
> > >>overlapping ranges from two different routers could cause packets to be
> > >>sent to the wrong destination. Summarization is done via the following
> > >>router ospf subcommand:
> > >>
> > >> summary-address ip-address mask
> > >>
> > >>This command is effective only on ASBRs doing redistribution into OSPF."
> > >>---
> > >>The above CCO verbiage WOULD seem to indicate that the command is
> > >>effective only one way. However, don't forget, this is an ASBR which
> > >>also has the duty to tell external networks about what routes are
> > >>available in the OSPF cloud.
> > >>
> > >>The configuration you gave is only the part where IGRP is redistributed
> > >>into OSPF:
> > >>
> > >>router ospf 100
> > >> router-id 4.4.4.4
> > >> log-adjacency-changes
> > >> summary-address 135.1.20.0 255.255.255.0
> > >> redistribute igrp 100 subnets
> > >>
> > >>I haven't seen the write-up in question, but you are correct that the
> > >>above configuration by itself does nothing to redistribute routes into
> > >>IGRP. To do that statements like the ones below are needed:
> > >>
> > >>router igrp
> > >> redistribute ospf 100 metric 10000 2000 255 1 1500 subnets
> > >>
> > >>And the trick here, is that since the 135.1.20.0/22 network has been
> > >>summarized in OSPF as a /24, then *that* /24 is what gets redistributed
> > >>into IGRP. This "trick" is necessary because IGRP won't understand the
> > >>classless subnets. Essentially, you are using the OSPF ASBR's summary
> > >>network statement to "adjust" the mask of OSPF classless networks to
> > >>something that IGRP will understand.
> > >>
> > >>HTH,
> > >>
> > >>Jonathan
> > >>
> > >>
> > >>-----Original Message-----
> > >>From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
> > >>Todd Spencer
> > >>Sent: Saturday, May 18, 2002 4:54 PM
> > >>To: ccielab@groupstudy.com
> > >>Subject: FATKID 502 Expert Redistribution
> > >>
> > >>
> > >>I am trying to do the FatKid 502 Expert Redistribution
> > >>Lab, and I don't understand the solution provided. I
> > >>will try to briefly explain.
> > >>
> > >>The problem has to do with the classic VLSM to FLSM
> > >>problem (IGRP/OSPF). The lab requires that OSPF area
> > >>4 be configured with a /22 subnet, and the IGRP domain
> > >>be configured with a /24. OSPF area 4 is using the
> > >>following subnet 135.1.20.x/22 and the IGRP domain is
> > >>using 135.1.1.x/24. The OSPF configuration below is
> > >>taken from the solution:
> > >>
> > >>router ospf 1
> > >> summary-address 135.1.20.0 255.255.255.0
> > >> redistribute igrp 1 subnets
> > >> network 135.1.14.0 0.0.0.255 area 4
> > >> network 135.1.20.0 0.0.3.255 area 4
> > >>
> > >>I am unsure what the summary-address command is doing
> > >>in this configuration. How is it able to summarize a
> > >>/22 into a /24? How is the /22 subnet getting into
> > >>the IGRP domain? If anyone has done this lab and can
> > >>provide assistance, it would be greatly appreciated.
> > >>
> > >>-Todd
> > >>
> > >>
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