IGP Comparison (Summary of Responses)
Niels Chr. Bank-Pedersen
ncbp at bank-pedersen.dk
Wed Jan 6 07:55:26 UTC 1999
On Tue, Jan 05, 1999 at 09:13:18PM -0600, Sean Donelan wrote:
> randy at psg.COM (Randy Bush) writes:
> >> Most of the large ISPs in the US run IS-IS as their IP IGP.
> >> In europe a number of PTTs have chosen IS-IS as the IGP for their new
> >> IP Internet backbones. That might be an indication if IS-IS is dead.
> >
> >hypothesis: big isps talk less. except a few loudmouths <g>, and when jhawk
> >gets pissed off <g^2>.
>
> I know why most of the older large ISPs use IS-IS, because it was the
> only option that worked at the time. But now that some router vendors
> have come out with workable OSPF implementations, I've been wondering
> which road the new ISP competitors would take. So far, they've been
> hiring all the engineering staff away from the older ISPs. And then
> the engineers set up the new network with the same skills, meaning IS-IS.
>
> But what if you started from a clean slate...
I know of one new network planned by people originally most familiar with
OSPF that is now running IS-IS. It did start out as OSPF allright, but
when you go beyond 200+ routers in area 0 within 6 months (and still
growing) you start wondering whether you shouldn't take a different
approach -- and thats when IS-IS comes in handy.
> If you didn't have an installed base, and didn't already know one or
> the other, which would you choose? Or just punt, and use iBGP....
I guess it depends on how large you plan to get :-)
- and yes, I know, that OSPF scales quite well if you design it
carefully WRT areas, but so does IS-IS...
Another way to look at it would be that you could keep on making
sloppy networkdesign far longer in an IS-IS network than you could with
OSPF ;)
> --
> Sean Donelan, Data Research Associates, Inc, St. Louis, MO
> Affiliation given for identification not representation
/Niels Chr.
--
Niels Christian Bank-Pedersen, NCB1-RIPE.
Network Manager, Tele Danmark NET, IP-section.
# rsh -l God universe.all find / -name '*windows*' -exec rm -rf {} \\;
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