From: Howard C. Berkowitz (hcb@gettcomm.com)
Date: Wed Feb 12 2003 - 00:50:14 GMT-3
At 10:06 PM -0500 2/11/03, Aaron Woody wrote:
>-----Original Message-----
>From: Aaron Woody [mailto:awoody@columbus.rr.com]
>Sent: Tuesday, February 11, 2003 9:50 PM
>To: Chuck Church
>Subject: RE: OSPF for 400+ Locations
>
>
>Chuck,
>
> That is correct 1 hub with all 400 remotes going to it via
>point-to-point
>sub interfaces. The host will be DS3, CIR's on PVC's will vary. OSPF area 0
>will have 3 routers, each remote area (400+) will have 1 router. Since each
>remote only needs 3 addresses I figure I can summarize each remote into the
>sub interface subnet. It will waste a little address space but if I don't I
>will have over 800 routes in table using their current scheme.
Summarization is good. Still, 800 routes is not a lot for a modern router.
> Currently
>they are using a 172.16.0.x/30 for WAN and 10.x.x.x/28 for LAN. Do you think
>I will be fine with that many areas. Also, should I extend area 0 across wan
>or should I place backbone router wan interface in remote area? Is there any
>difference?
>
If it's pure point-to-point hub-and-spoke, with alternate paths, why
do you need a routing protocol at all? If that's the case, I'd use
static routes.
As to using OSPF, 400 areas easily could be too many, since your hub
router would have to have an LSDB and other structures for each area.
As others have suggested, you must define a sensible addressing plan.
Now, you are going to have to know how those addresses are assigned,
and presumably are going to use a spreadsheet or database for that.
If you have systematic addressing, it's fairly simple to define
reports that create the necessary static routes in both direction,
and merge them with the appropriate configuration. See my NANOG
presentation at http://www.nanog.org/mtg-9811/ppt/berk/index.htm or
look at any of my books--maybe not "Designing Routing Architectures,"
but certainly the others.
>
>-----Original Message-----
>From: Chuck Church [mailto:ccie8776@rochester.rr.com]
>Sent: Tuesday, February 11, 2003 9:33 PM
>To: Aaron Woody; ccielab@groupstudy.com
>Subject: Re: OSPF for 400+ Locations
>
>
>Aaron,
>
> When you say hub and spoke, is there just one hub with all 400 spokes
>going to that? What is the CIR at both the spoke end and the hub end? Is
>there any redundancy, like dial backup? Try to keep your areas to 20 to 30
>routers in each. With some careful planning, especially with the addressing
>(make is summarizable), it'll work fine.
>
>Chuck Church
>CCIE #8776, MCNE, MCSE
>
>
>----- Original Message -----
>From: "Aaron Woody" <awoody@columbus.rr.com>
>To: <ccielab@groupstudy.com>
>Sent: Tuesday, February 11, 2003 6:21 PM
>Subject: OSPF for 400+ Locations
>
>
>> I have experience with OSPF but I am looking for suggestions on how to
>> implement OSPF in a Frame-Relay Hub/Spoke topology for 400+ locations.
>Each
>> location only needs to know about the host through a default. My first
>idea
>> is to have a separate area for each location and make it a totally stubby
>> area. Is there a better way. My concern is that there will be 400+ areas
>in
>> the OSPF Database at the host. The host will be a Cisco 3745. The remotes
>> will all be Cisco 1751.
>>
>> Thanks!
>>
>> Aaron
>>
>> [GroupStudy.com removed an attachment of type application/ms-tnef which
>had a name of winmail.dat]
>> .
>.
.
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