"Howard C. Berkowitz" wrote:
> At 4:07 PM -0400 6/16/02, Neal Rauhauser 402-301-9555 wrote:
> >My only explanation for this is that there was nothing good on TV on a
> >lazy Sunday morning ...
> >
> > I am about to start doing some truly gruesome things with IBGP due to
> >geographical separate peering points and I've got some internal routers
> >that are maxed out at 64 meg, so I spent a little time this AM examining
> >the source of this silly 114k+ entry global BGP table. My idea was that
> >a carrier stuck smack in the middle of the US could probably ignore
> >details about RIPE and APIC address space. Those two authorities turn
> >out to be responsible for only about 32k of the total so I am casting
> >around for other methods to trim the fat but I thought I'd share the
> >results thus far.
>
> You'll find a LARGE part of the routing table still comes from the
> Swamp [1] or the Toxic Waste Dump [2], rather than any geographical
> region.
>
> Neal, this is a distinctly nontrivial problem, with no ideal
> solution. Your basic choice is accepting "suboptimal routing [3]" or
> upgrading your routers.
>
> Several basic questions come up about what you are trying to do:
>
> 1. Is this for an ISP or an enterprise?
Internet provider, doing wireless, playing with private line replacement
stuff, too.
>
> 2. From a bandwidth standpoint, how many peering points could you
> lose and still have acceptable performance?
I've got a single Sprint T1 at one end of the network, an AT&T and
UUNet T1 at the
other end. The Sprint side will grow quickly to more capacity, the AT&T and
UUNet stuff
is a colo company, not mine to rule, so they're fussy about how much output
we
generate, but don't care much about our input side.
>
> 3. To how many different AS do you connect, and do they have
> approximately
> equal connectivity?
Sprint, AT&T, UUNet, probably going to add one more at the end where the
Sprint
circuit is, but I suspect it'll be UUNet there, too.
>
> 4. What is your IGP?
Today its OSPF and that is the one I know best. There is some cause to
consider
replacing OSPF area 0 with EIGRP due to different cost links and varying
'cleanliness'
in the wireless layer, but we'll see how that goes - I have enough to do
without
worrying about redistribution right now.
>
> 5. How much effort, including programming, are you willing to do to
> optimize tables?
Lots and lots ... keeps me off the street and contributes to passing my
CCIP BSCI
exam I think ...
>
> 6. Do you have a decent familiarity with RPSL, routing registry, and
> some
> of the freeware tools such as CIDRadvisor and RtConfig?
>
I've made a few basic entries in the RADB, I've played with cflowd,
and I've not
done much with the automation tools in this area. I'll prefer to hand tune
at first,
until I really understand what I am facing.
>
> Howard
>
> [1] The Swamp is the term used in addressing working groups to refer
> to 192.0.0.0/8, the original Class C space.
>
> [2] The Toxic Waste Dump, which probably is somewhere in Northern New
> Jersey, is that part of the Swamp containing /24 or longer prefixes.
>
> [3] People often worry about suboptimal routing, but the gains of one
> "perfect"
> path may be marginal when compared with the complexity of
> differentiating it from a "decent" route.
>
> --
> "What Problem are you trying to solve?"
> ***send Cisco questions to the list, so all can benefit -- not
> directly to me***
>
********************************************************************************
> Howard C. Berkowitz [EMAIL PROTECTED]
> Chief Technology Officer, GettLab/Gett Communications
http://www.gettlabs.com
> Technical Director, CertificationZone.com http://www.certificationzone.com
> "retired" Certified Cisco Systems Instructor (CID) #93005
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